Chromium-catalyzed production of diols from olefins

ABSTRACT

Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.

REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/900,687, filed on Sep. 16, 2019, the disclosure ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present disclosure generally relates to methods for convertingolefins into diols, and more particularly, relates to performing suchmethods with a supported chromium catalyst.

BACKGROUND OF THE INVENTION

Various diol compounds can be prepared by numerous synthesis techniques,such as the hydrolysis of epoxides, the oxidation of olefins using withacidic potassium permanganate or osmium tetroxide, and the condensationof ketones with formaldehyde followed by hydrogenation. Alternativereaction schemes are desirable. Accordingly, it is to this end that thepresent invention is generally directed.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

Aspects of this invention are directed to processes for converting anolefin reactant into a diol compound. For example, in one aspect, afirst process can comprise (i) contacting the olefin reactant and asupported chromium catalyst comprising chromium in a hexavalentoxidation state to reduce at least a portion of the supported chromiumcatalyst to form a reduced chromium catalyst, and (ii) hydrolyzing thereduced chromium catalyst to form a reaction product comprising the diolcompound. In another aspect, a second process for converting an olefinreactant into a diol compound can comprise (i) irradiating the olefinreactant and a supported chromium catalyst comprising chromium in ahexavalent oxidation state with a light beam at a wavelength in theUV-visible spectrum to reduce at least a portion of the supportedchromium catalyst to form a reduced chromium catalyst, and (ii)hydrolyzing the reduced chromium catalyst to form a reaction productcomprising the diol compound. Optionally, these processes can furthercomprise a step of (iii) calcining the reduced chromium catalyst toregenerate the supported chromium catalyst.

In step (i), at least a portion of the chromium on the reduced chromiumcatalyst can have at least one bonding site with a hydrocarboxy group (a—O-hydrocarbon group), which upon hydrolysis in step (ii), can release adiol compound analog of the olefin compound. For instance, if the olefinreactant is 1-hexene, then the diol compound can be 1,2-hexanediol.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain aspects may bedirected to various feature combinations and sub-combinations describedin the detailed description.

Definitions

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2^(nd) Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

Herein, features of the subject matter are described such that, withinparticular aspects, a combination of different features can beenvisioned. For each and every aspect and each and every featuredisclosed herein, all combinations that do not detrimentally affect thecatalysts, compositions, processes, or methods described herein arecontemplated with or without explicit description of the particularcombination. Additionally, unless explicitly recited otherwise, anyaspect or feature disclosed herein can be combined to describe inventivecatalysts, compositions, processes, or methods consistent with thepresent disclosure.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, transition metals for Group 3-12 elements,and halogens or halides for Group 17 elements.

The term “hydrocarbon” whenever used in this specification and claimsrefers to a compound containing only carbon and hydrogen, whethersaturated or unsaturated. Other identifiers can be utilized to indicatethe presence of particular groups in the hydrocarbon (e.g., halogenatedhydrocarbon indicates the presence of one or more halogen atomsreplacing an equivalent number of hydrogen atoms in the hydrocarbon).Non-limiting examples of hydrocarbons include alkanes (linear, branched,and cyclic), alkenes (olefins), and aromatics, among other compounds.Herein, cyclics and aromatics encompass fused ring compounds such asbicyclics and polycyclics.

For any particular compound or group disclosed herein, any name orstructure (general or specific) presented is intended to encompass allconformational isomers, regioisomers, stereoisomers, and mixturesthereof that can arise from a particular set of substituents, unlessotherwise specified. The name or structure (general or specific) alsoencompasses all enantiomers, diastereomers, and other optical isomers(if there are any) whether in enantiomeric or racemic forms, as well asmixtures of stereoisomers, as would be recognized by a skilled artisan,unless otherwise specified. For instance, a general reference to pentaneincludes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane; and ageneral reference to a butyl group includes a n-butyl group, a sec-butylgroup, an iso-butyl group, and a t-butyl group.

Unless otherwise specified, the term “substituted” when used to describea group, for example, when referring to a substituted analog of aparticular group, is intended to describe any non-hydrogen moiety thatformally replaces a hydrogen in that group, and is intended to benon-limiting. Also, unless otherwise specified, a group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen within that group.Moreover, unless otherwise specified, “substituted” is intended to benon-limiting and include inorganic substituents or organic substituentsas understood by one of ordinary skill in the art.

The terms “contacting” and “combining” are used herein to describecatalysts, compositions, processes, and methods in which the materialsor components are contacted or combined together in any order, in anymanner, and for any length of time, unless otherwise specified. Forexample, the materials or components can be blended, mixed, slurried,dissolved, reacted, treated, impregnated, compounded, or otherwisecontacted or combined in some other manner or by any suitable method ortechnique.

“BET surface area” as used herein means the surface area as determinedby the nitrogen adsorption Brunauer, Emmett, and Teller (BET) methodaccording to ASTM D1993-91, and as described, for example, in Brunauer,S., Emmett, P. H., and Teller, E., “Adsorption of gases inmultimolecular layers,” J. Am. Chem. Soc., 60, 3, pp. 309-319, thecontents of which are expressly incorporated by reference herein.

In this disclosure, while catalysts, compositions, processes, andmethods are described in terms of “comprising” various components orsteps, the catalysts, compositions, processes, and methods also can“consist essentially of” or “consist of” the various components orsteps, unless stated otherwise.

The terms “a,” “an,” and “the” are intended to include pluralalternatives, e.g., at least one. For instance, the disclosure of “anolefin reactant,” “a solid oxide,” etc., is meant to encompass one, ormixtures or combinations of more than one, olefin reactant, solid oxide,etc., unless otherwise specified.

Several types of ranges are disclosed in the present invention. When arange of any type is disclosed or claimed, the intent is to disclose orclaim individually each possible number that such a range couldreasonably encompass, including end points of the range as well as anysub-ranges and combinations of sub-ranges encompassed therein. Forexample, when a chemical compound having a certain number of carbonatoms is disclosed or claimed, the intent is to disclose or claimindividually every possible number that such a range could encompass,consistent with the disclosure herein. For example, the disclosure thatan olefin reactant contains a C₂ to C₁₈ olefin compound, or inalternative language, an olefin compound having from 2 to 18 carbonatoms, as used herein, refers to a compound that can have 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms, as well asany range between these two numbers (for example, a C₂ to C₈ olefincompound), and also including any combination of ranges between thesetwo numbers (for example, a C₂ to C₄ olefin compound and a C₈ to C₁₂olefin compound).

Similarly, another representative example follows for the amount ofchromium on the supported chromium catalyst consistent with aspects ofthis invention. By a disclosure that the amount of chromium can be in arange from about 0.1 to about 15 wt. %, the intent is to recite that theamount of chromium can be any amount in the range and, for example, canbe equal to about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about0.6, about 0.7, about 0.8, about 0.9, about 1, about 2, about 3, about4, about 5, about 6, about 7, about 8, about 9, about 10, about 11,about 12, about 13, about 14, or about 15 wt. %. Additionally, theamount of chromium can be within any range from about 0.1 to about 15wt. % (for example, from about 0.1 to about 5 wt. %), and this alsoincludes any combination of ranges between about 0.1 and about 15 wt. %(for example, the amount of chromium can be in a range from about 0.5 toabout 2.5 wt. %, or from about 5 to about 15 wt. %). Further, in allinstances, where “about” a particular value is disclosed, then thatvalue itself is disclosed. Thus, the disclosure that the amount ofchromium can be from about 0.1 to about 15 wt. % also discloses anamount of chromium from 0.1 to 15 wt. % (for example, from 0.1 to 5 wt.%), and this also includes any combination of ranges between 0.1 and 15wt. % (for example, the amount of chromium can be in a range from 0.5 to2.5 wt. %, or from 5 to 15 wt. %). Likewise, all other ranges disclosedherein should be interpreted in a manner similar to these examples.

The term “about” means that amounts, sizes, formulations, parameters,and other quantities and characteristics are not and need not be exact,but can be approximate including being larger or smaller, as desired,reflecting tolerances, conversion factors, rounding off, measurementerrors, and the like, and other factors known to those of skill in theart. In general, an amount, size, formulation, parameter or otherquantity or characteristic is “about” or “approximate” whether or notexpressly stated to be such. The term “about” also encompasses amountsthat differ due to different equilibrium conditions for a compositionresulting from a particular initial mixture. Whether or not modified bythe term “about,” the claims include equivalents to the quantities. Theterm “about” can mean within 10% of the reported numerical value, andoften within 5% of the reported numerical value.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices, and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is generally directed to the conversion of anolefin into an analogous diol compound. Unexpectedly, it was found thatthe combined use of a supported chromium catalyst, light reduction, andhydrolysis can efficiently convert the olefin (e.g., a normal α-olefin)into the analogous diol, and beneficially, even at ambient temperature.Also unexpectedly, it was found that in some olefin-to-dioltransformations, light reduction was not required, such as for certainnormal α-olefin reactants.

Processes for Converting Olefins into Diols

Disclosed herein are processes for converting an olefin reactant into adiol compound. A first process can comprise (i) contacting the olefinreactant and a supported chromium catalyst comprising chromium in ahexavalent oxidation state to reduce at least a portion of the supportedchromium catalyst to form a reduced chromium catalyst, and (ii)hydrolyzing the reduced chromium catalyst to form a reaction productcomprising the diol compound. A second process can comprise (i)irradiating the olefin reactant and a supported chromium catalystcomprising chromium in a hexavalent oxidation state with a light beam ata wavelength in the UV-visible spectrum to reduce at least a portion ofthe supported chromium catalyst to form a reduced chromium catalyst, and(ii) hydrolyzing the reduced chromium catalyst to form a reactionproduct comprising the diol compound. The reduced chromium catalyst hasan average oxidation state less than that of the supported chromiumcatalyst.

While not wishing to be bound by theory, it is believed that in step (i)of the first and second processes, at least a portion of the chromium onthe reduced chromium catalyst can have at least one bonding site with ahydrocarboxy group (a —O-hydrocarbon group), which upon hydrolysis instep (ii), can release a diol compound analog of the olefin reactant.For instance, and not wishing to be bound by theory, a double alkoxidelinkage may be formed with α-olefins, in which the first and secondcarbons bond to adjacent oxygens on the reduced chromium catalyst, whichupon hydrolysis can release a 1,2-diol compound analog of the α-olefinreactant.

Generally, the features of the first process and the second process(e.g., the olefin reactant, the supported chromium catalyst, the reducedchromium catalyst, the light beam, and the conditions under which thecontacting step (or the irradiating step) and the hydrolyzing step areconducted, among others) are independently described herein and thesefeatures can be combined in any combination to further describe thedisclosed processes to produce diol compounds. Moreover, additionalprocess steps can be performed before, during, and/or after any of thesteps in any of the processes disclosed herein, and can be utilizedwithout limitation and in any combination to further describe theseprocesses, unless stated otherwise. Further, any diol compounds producedin accordance with the disclosed processes are within the scope of thisdisclosure and are encompassed herein.

A variety of olefin reactants can be used in the processes to form adiol compound, inclusive of linear olefin compounds (e.g., normalα-olefins), branched olefin compounds, cyclic olefin compounds, and thelike, as well as combinations thereof. Any suitable carbon number olefincan be used, such that the olefin reactant can comprise a Cn olefincompound (and the diol compound often can comprise a Cn diol compound).While not being limited thereto, the integer n can range from 2 to 36 inone aspect, from 2 to 18 in another aspect, from 2 to 12 in yet anotheraspect, and from 2 to 8 in still another aspect.

Therefore, the olefin reactant can comprise any suitable carbon numberolefin compound, for instance, a C₂ to C₃₆ olefin compound;alternatively, a C₂ to C₁₈ olefin compound; alternatively, a C₂ to C₁₂olefin compound; alternatively, a C₂ to C₈ olefin compound;alternatively, a C₂-C₁₅ normal α-olefin compound; or alternatively, aC₂-C₈ normal α-olefin compound. If desired, the olefin reactant cancontain a single olefin compound of relatively high purity, such as atleast about 90 wt. % of a single olefin compound, at least about 95 wt.% of a single olefin compound, at least about 98 wt. % of a singleolefin compound, or at least about 99 wt. % of a single olefin compound,and so forth. Alternatively, the olefin reactant can comprise a mixtureof two or more olefin reactants, such as two or more olefin compounds inany relative proportions. Thus, the olefin reactant can comprise amixture of C₂ to C₃₆ olefin compounds, a mixture of C₂ to C₁₈ olefincompounds, a mixture of C₂ to C₁₂ olefin compounds, or a mixture of C₂to C₈ olefin compounds, and the like.

Illustrative examples of olefin reactants can include ethylene,propylene, butene, pentene, hexene, heptene, octene, decene, dodecene,tetradecene, hexadecene, octadecene, and the like, as well ascombinations thereof. In a non-limiting aspect, the olefin reactant cancomprise ethylene, propylene, 1-butene, 2-butene, 3-methyl-1-butene,isobutylene, 1-pentene, 2-pentene, 3-methyl-1-pentene,4-methyl-1-pentene, 1-hexene, 2-hexene, 3-ethyl-1-hexene, 1-heptene,2-heptene, 3-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene,1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene,1-octadecene, styrene, and the like, as well as combinations thereof. Inanother aspect, the olefin reactant can comprise ethylene, propylene,1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene,1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and the like, orany combination thereof. In yet another aspect, the olefin reactant cancomprise ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and thelike, or any combination thereof. In still another aspect, the olefinreactant can comprise norbornene, cyclopentene, cyclohexene,cycloheptene, cyclooctene, and the like, or any combination thereof.

In the second process, the olefin reactant and the supported chromiumcatalyst can be irradiated with a light beam at a wavelength in theUV-visible spectrum, while in the first process, the olefin reactant andthe supported chromium catalyst can be contacted in the absence of lightirradiation. While light irradiation is beneficial and may be needed forcertain olefin-to-diol transformations, it is not required for allolefin-to-diol transformations. For instance, and unexpectedly,α-olefins such as 1-pentene and 1-hexene are sufficiently reactive withthe supported chromium catalyst to produce diols after hydrolysis in theabsence of any light irradiation.

Generally, the contacting step of the first process can be performedunder any conditions sufficient to accommodate the contacting of theolefin reactant and the supported chromium catalyst (comprising chromiumin a hexavalent oxidation state) to form the reduced chromium catalyst(having a lower oxidation state), while the irradiating step of thesecond process can be performed under any conditions sufficient toaccommodate the irradiation of the olefin reactant and the supportedchromium catalyst (comprising chromium in a hexavalent oxidation state)with a light beam and to form the reduced chromium catalyst (having alower oxidation state). For instance, the relative amount (orconcentration) of the olefin reactant to the amount of chromium (in thesupported chromium catalyst) can alter the efficacy of the reductionprocess. In certain aspects, the molar ratio of the olefin reactant tothe chromium (in the supported chromium catalyst) can be at least about0.25:1, at least about 0.5:1, at least about 1:1, at least about 10:1,at least about 100:1, at least about 1000:1, or at least about 10,000:1.Thus, a large excess of the olefin reactant can be used, and there is noparticular limit as to the maximum amount of olefin reactant.

The temperature and pressure of the contacting step (or the irradiatingstep) can be such that the olefin reactant remains a liquid throughoutreduction of the supported chromium catalyst in one aspect, and theolefin reactant remains a gas throughout reduction of the supportedchromium catalyst in another aspect. Advantageously, it was found thatreducing supported chromium compounds at ambient temperatures wasachieved in both the first process and the second process disclosedherein. Nonetheless, in certain aspects, the contacting step (or theirradiating step) can be conducted at a temperature of less than about200° C., less than about 100° C., less than about 70° C., less thanabout 40° C., from about 0° C. to about 200° C., from about −100° C. toabout 100° C., from about 0° C. to about 100° C., or from about 10° C.to about 40° C., and can produce a reduced chromium catalyst (e.g., withat least a portion of the chromium on the reduced chromium catalysthaving at least one bonding site with a hydrocarboxy group). Thesetemperature ranges also are meant to encompass circumstances where thecontacting (or the irradiating) is performed at a series of differenttemperatures, instead of at a single fixed temperature, falling withinthe respective temperature ranges, wherein at least one temperature iswithin the recited ranges.

In the first process, the contacting step can be further characterizedby an amount of time that the olefin reactant and the supported chromiumcatalyst are contacted or combined, e.g., a contact time. The contacttime must be sufficient to allow the reduction of the supported chromiumcatalyst to occur, whether the reduction occurs very rapidly or veryslowly. Thus, in certain aspects, and not being limited thereto, thecontact time can be in a range from about 15 sec to about 48 hr, fromabout 15 sec to about 24 hr, from about 1 hr to about 8 hr, from about15 min to about 4 hr, from about 1 min to about 6 hr, from about 5 minto about 1 hr, from about 10 min to about 2 hr, from about 1 min toabout 1 hr, or from about 1 min to about 15 min. Agitation, mixing, orother suitable technique can be used to ensure that the mixture of thesupported chromium catalyst (e.g., particles) and the olefin reactant isuniformly combined.

Likewise, in the second process, the irradiating step can be furthercharacterized by an amount of time that the olefin reactant and thesupported chromium catalyst are exposed to the light beam, e.g., anexposure time. Without being bound by theory, it is believed thatexposure to the light beam in the presence of the olefin reactant isresponsible for the reduction of the supported chromium catalyst, andtherefore it follows that the exposure time must be sufficient to allowthis transformation to occur, whether the transformation occurs veryrapidly or very slowly. Thus, in certain aspects, and not being limitedthereto, the exposure time can be in a range from about 15 sec to about48 hr, from about 15 sec to about 24 hr, from about 1 hr to about 8 hr,from about 15 min to about 4 hr, from about 1 min to about 6 hr, fromabout 5 min to about 1 hr, from about 10 min to about 2 hr, from about 1min to about 1 hr, or from about 1 min to about 15 min. As one of skillin the art would recognize, the exposure time can vary based on theintensity of the light beam, the wavelength(s) of the light beam, and soforth. Agitation, mixing, or other suitable technique can be used toensure that the mixture of the supported chromium catalyst (e.g.,particles) and the olefin reactant is uniformly exposed to the lightbeam irradiation.

The supported chromium catalyst and the olefin reactant can becontinuously subjected to irradiation (for the entirety of the exposuretime), or the irradiation can be pulsed (such that the total of thepulses equates to the exposure time, e.g., sixty 1-sec pulses equates toa 60-sec exposure time). Combinations of periods of continuousirradiation and pulsed irradiation can be utilized, if desired.

In the second process, irradiation of a supported chromium catalyst witha light beam in the UV-visible spectrum, in the presence of an olefinreactant, results in a chromium catalyst with a reduced oxidation state(e.g., a reduced chromium catalyst). A wide range of wavelengths, lightsources, and intensities can be used, as long as these wavelengths,light sources, and intensities are sufficient to reduce at least aportion of the hexavalent chromium species present in the supportedchromium catalyst. In certain aspects, for instance, the light can bederived from any suitable source, such as from sunlight, a fluorescentwhite light, an LED diode, and/or a UV lamp. The distance fromnon-sunlight sources can be varied as needed (e.g., minimized) toincrease the effectiveness of the irradiation.

The wavelength of the light can be any in the range of UV-visible light.In certain aspects, the wavelength of the light beam can be a singlewavelength, or more than one wavelength, such as a range of wavelengths.For instance, the wavelength of the light beam can be a range ofwavelengths spanning at least 25 nm, at least 50 nm, at least 100 nm, atleast 200 nm, or at least 300 nm. In one aspect, the wavelength of thelight beam can comprise a single wavelength or a range of wavelengths inthe UV spectrum, in the visible spectrum (from 380 nm to 780 nm), orboth. In another aspect, the wavelength of the light beam can comprise asingle wavelength or a range of wavelengths in the 200 nm to 750 nmrange. Yet, in another aspect, the wavelength of the light beam cancomprise a single wavelength or a range of wavelengths in the 300 to 750nm range, the 350 nm to 650 nm range, the 300 nm to 600 nm range, the300 nm to 500 nm range, or the 400 nm to 500 nm range. In other aspects,the wavelength of the light beam can comprise a single wavelength or arange of wavelengths below 600 nm, below 525 nm, or below 500 nm;additionally or alternatively, above 300 nm, above 350 nm, above 400 nm,or above 450 nm.

The light beam of the irradiating step also can be characterized by itsintensity (e.g., the total amount of light emitted from a source). Incertain aspects, the light beam can have an intensity of at least about500 lumens, at least about 1,000 lumens, at least about 2,000 lumens atleast about 5,000 lumens, at least about 10,000 lumens, at least about20,000 lumens, at least about 50,000 lumens, or at least about 100,000lumens. Thus, there may not be an upper limit on the intensity of thelight source. Alternatively, the light beam can have an intensity in arange from about 50 to about 50,000 lumens, from about 50 to about10,000 lumens, from about 100 to about 5,000 lumens, or from about 500to about 2,000 lumens. Additionally, the light beam can be characterizedby the amount of light reaching the olefin reactant and supportedchromium catalyst, i.e., the flux. In certain aspects, the olefinreactant and the supported chromium catalyst comprising chromium in ahexavalent oxidation state can be irradiated by at least about 100 lux,at least about 500 lux, at least about 1000 lux, at least about 2000lux, at least about 5000 lux, at least about 10,000 lux, at least about20,000 lux, at least about 100,000 lux, or in a range from about 10,000to about 1,000,000 lux, from about 50,000 to about 500,000 lux, or fromabout 50,000 to about 200,000 lux. Additionally or alternatively, incertain aspects, the olefin reactant and the supported chromium catalystcomprising chromium in the hexavalent oxidation state can be irradiatedwith a light beam having a power of at least about 50 watts, at leastabout 100 watts, at least about 200 watts, at least about 500 watts, atleast about 1,000 watts, or at least about 2,000 watts.

Any suitable reactor or vessel can be used to form the diol compound,non-limiting examples of which can include a flow reactor, a continuousreactor, a packed bed reactor, a fluidized bed reactor, and a stirredtank reactor, including more than one reactor in series or in parallel,and including any combination of reactor types and arrangements.

In one aspect, the olefin reactant can be in a gas phase during thecontacting step (or the irradiating step). In another aspect, the olefinreactant can be in a liquid phase during the contacting step (or theirradiating step). In another aspect, the disclosed processes cancomprise contacting (or irradiating) a slurry (e.g., a loop slurry) ofthe solid supported chromium catalyst in the olefin reactant. In yetanother aspect, the disclosed processes can comprise contacting theolefin reactant with a fluidized bed of the solid supported chromiumcatalyst (or irradiating while contacting or fluidizing the supportedchromium catalyst). In still another aspect, the disclosed processes cancomprise contacting the olefin reactant (e.g., in the gas phase or inthe liquid phase) with a fixed bed of the solid supported chromiumcatalyst (or irradiating while contacting). As a skilled artisan wouldrecognize, there are other methods for contacting/irradiating the olefinreactant and the solid supported chromium catalysts, and the disclosedprocesses are not limited solely to those disclosed herein. Forinstance, the olefin reactant and the supported chromium catalyst can bemixed or contacted in a stirred tank (or irradiated while being mixed inthe stirred tank).

Any suitable pressure can be used to contact the olefin reactant and thesupported catalyst and to form the reduced chromium catalyst, and suchcan depend upon the carbon number of the olefin reactant (and itsboiling point), the type of reactor configuration and desired mode forcontacting/irradiating the olefin reactant with the (solid) supportedchromium catalyst, among other considerations.

Often, the process for forming the reduced chromium catalyst (andsubsequently, the diol compound) can be a flow process and/or acontinuous process. In such circumstances, the olefin reactant-supportedchromium catalyst contact time (or reaction time) can be expressed interms of weight hourly space velocity (WHSV) the ratio of the weight ofthe olefin reactant which comes in contact with a given weight of thesupported chromium catalyst per unit time (units of g/g/hr, or hr⁻¹).

While not limited thereto, the WHSV employed for the disclosed processescan have a minimum value of 0.01 hr⁻¹, 0.02 hr⁻¹, 0.05 hr⁻¹, 0.1 hr⁻¹,0.25 hr⁻¹, or 0.5 hr⁻¹; or alternatively, a maximum value of 500 hr⁻¹,400 hr⁻¹, 300 hr⁻¹, 100 hr⁻¹, 50 hr⁻¹, 10 hr⁻¹, 5 hr⁻¹, 2 hr⁻¹, or 1hr⁻¹. Generally, the WHSV can be in a range from any minimum WHSVdisclosed herein to any maximum WHSV disclosed herein. In a non-limitingaspect, the WHSV can be in a range from about 0.01 hr⁻¹ to about 500hr⁻¹; alternatively, from about 0.01 hr⁻¹ to about 10 hr⁻¹;alternatively, from about 0.01 hr⁻¹ to about 1 hr⁻¹; alternatively, fromabout 0.02 hr⁻¹ to about 400 hr⁻¹; alternatively, from about 0.02 hr⁻¹to about 50 hr⁻¹; alternatively, from about 0.05 hr⁻¹ to about 300 hr⁻¹;alternatively, from about 0.05 hr⁻¹ to about 5 hr⁻¹; alternatively, fromabout 0.1 hr⁻¹ to about 400 hr⁻¹; alternatively, from about 0.25 hr⁻¹ toabout 50 hr⁻¹; alternatively, from about 0.25 hr⁻¹ to about 2 hr⁻¹;alternatively, from about 0.5 hr⁻¹ to about 400 hr⁻¹; alternatively,from about 0.5 hr⁻¹ to about 5 hr⁻¹; or alternatively, from about 0.5hr⁻¹ to about 2 hr⁻¹. Other WHSV ranges are readily apparent from thisdisclosure.

Referring now to the hydrolyzing step, in which the reduced chromiumcatalyst (e.g., with at least a portion of the chromium on the reducedchromium catalyst having at least one bonding site with a hydrocarboxygroup) is hydrolyzed to form a reaction product comprising the diolcompound. Generally, the temperature, pressure, and time features of thehydrolyzing step can be the same as those disclosed herein for thecontacting step or irradiating step, although not limited thereto. Forexample, the hydrolyzing step can be conducted at a temperature of lessthan about 200° C., less than about 100° C., less than about 70° C.,less than about 40° C., from about 0° C. to about 200° C., from about 0°C. to about 100° C., or from about 10° C. to about 40° C., and canresult in the formation of a reaction product containing the diolcompound. These temperature ranges also are meant to encompasscircumstances where the hydrolyzing step is performed at a series ofdifferent temperatures, instead of at a single fixed temperature,falling within the respective temperature ranges, wherein at least onetemperature is within the recited ranges.

While not limited thereto, the hydrolyzing step can comprise contactingthe reduced chromium catalyst with a hydrolysis agent. Illustrative andnon-limiting examples of suitable hydrolysis agents can include water,steam, an alcohol agent, an acid agent, an alkaline agent, and the like,as well as combinations thereof. Thus, mixtures of water and variousalcohol agents, such as C₁-C₄ alcohols (and/or acid agents, such ashydrochloric acid, sulfuric acid, acetic acid, ascorbic acid, and thelike; and/or alkaline agents, such as sodium hydroxide, ammoniumhydroxide, and the like) in any relative proportions can be used as thehydrolysis agent. Thus, the pH of the hydrolysis agent(s) can range fromacid to neutral to basic pH values, generally encompassing a pH rangefrom about 1 (or less) to about 13-13.5.

Optionally, the hydrolysis agent can further comprise any suitablereducing agent, and representative reducing agents include ascorbicacid, iron (II) reducing agents, zinc reducing agents, and the like, aswell as combinations thereof. These are sometimes useful for preventingunwanted secondary oxidations by unreacted chromium (VI). Further, theyalso can be used to tailor the product range by increasing selectivity.For example, in some aspects, adding reducing agents to the hydrolysisagent can eliminate all carbonyl products and instead produce onlyalcohol products.

As disclosed herein, the reaction product can comprise a diol compound,which can be an analog of the olefin reactant. Thus, typical diolcompounds that can synthesized using the processes disclosed herein caninclude, for instance, ethanediol (ethylene glycol), propanediol(propylene glycol), a butanediol, a pentanediol, a hexanediol, and thelike, as well as combinations thereof. Further, the diol compounds thatcan be synthesized using the processes disclosed herein can include a1,2-diol compound, or a 1,3-diol compound, or a 2,3-diol compound, orany combination of a 1,2-diol compound, a 1,3-diol compound, and/or a2,3-diol compound.

In addition to or in lieu of the diol compound, the reaction product cancomprise an alcohol compound (a mono-alcohol compound) and/or a carbonylcompound, such as an aldehyde compound, a ketone compound, or acarboxylic acid compound, as well as any combination of alcohol,aldehyde, ketone, and carboxylic acid compounds. Thus, enols areencompassed herein, since the reaction product can comprise an alcoholcompound, a carbonyl compound, or both.

The processes described herein result in an unexpectedly high conversionof the olefin reactant and/or yield to the diol compound. In one aspect,the minimum conversion (or yield) can be at least about 2 wt. %, atleast about 5 wt. %, at least about 10 wt. %, at least about 15 wt. %,or at least about 25 wt. %. Additionally, the maximum conversion (oryield) can be about 50 wt. %, about 70 wt. % about 80 wt. %, about 90wt. %, about 95 wt. %, or about 99 wt. %, and can approach 100%conversion of the olefin reactant (or yield of the diol compound).Generally, the conversion (or yield) can be in a range from any minimumconversion (or yield) disclosed herein to any maximum conversion (oryield) disclosed herein. Non-limiting ranges of conversion (or yield)can include from about 5 wt. % to about 99 wt. %, from about 10 wt. % toabout 95 wt. %, or from about 15 wt. % to about 70 wt. %. Forconversion, the percentages are the amount of the olefin reactantconverted based on the initial amount of the olefin reactant. The yieldvalues are weight percentages, and are based on the weight of the diolcompound produced to the weight of olefin reactant. In some aspects,these conversions (or yields) can be achieved in a batch process, whilein other aspects, these conversions (or yields) can be achieved in aflow or continuous process, such as, for example, a single pass ormultiple passes through a reactor (e.g., a fixed bed reactor). Often,the conversion and yield can be manipulated by varying the ratio ofreductant olefin feed to the amount of chromium (VI), and by varyingother reaction conditions such as time, temperature, and irradiation.

Also unexpectedly, continuous flow processes for producing the diolcompound in accordance with this invention have unexpectedly high singlepass conversions of the olefin reactant (or single pass yields to thedesired diol compound). In one aspect, the minimum single passconversion (or yield) can be at least about 2 wt. %, at least about 5wt. %, at least about 10 wt. %, at least about 15 wt. %, or at leastabout 25 wt. %. Additionally, the maximum single pass conversion (oryield) can be about 50 wt. %, about 70 wt. %, about 80 wt. %, about 90wt. %, about 95 wt. %, or about 99 wt. %, and can approach 100%conversion of the olefin reactant (or yield of the diol compound),depending upon the reaction conditions. Generally, the single passconversion (or yield) can be in a range from any minimum single passconversion (or yield) disclosed herein to any maximum single passconversion (or yield) disclosed herein. Non-limiting ranges of singlepass conversion (or yield) can include from about 5 wt. % to about 99wt. %, from about 10 wt. % to about 95 wt. %, or from about 15 wt. % toabout 70 wt. %.

The yield of the diol compound also can be characterized based on theamount of chromium (VI) (of the supported chromium catalyst). Forinstance, the molar ratio (molar yield) of the diol compound based onthe moles of chromium (VI) can be at least about 0.01 moles, at leastabout 0.02 moles, at least about 0.05 moles, at least about 0.1 moles,or at least about 0.25 moles (and up to 2 moles, up to about 1.8 moles,up to about 1.6 moles, up to about 1.4 moles, up to about 1.2 moles, orup to about 1 mole) of the diol compound per mole of chromium (VI). Ifmore than one diol compound is produced, then this ratio represents thetotal moles of diol compounds produced per mole of chromium (VI) of thesupported chromium catalyst.

The processes to produce the diol compounds disclosed herein typicallycan result in—after hydrolysis—a crude reaction mixture containingresidual olefin reactant (e.g., 1-hexene), a desired diol compound(e.g., 1,2-hexanediol), and by-products. In many instances, it can bedesirable to isolate or separate at least a portion (and in some cases,all) of the olefin reactant from the reaction product after step (ii).This can be accomplished using any suitable technique, which can includebut is not limited to, extraction, filtration, evaporation, ordistillation, as well as combinations of two or more of thesetechniques. In particular aspects of this invention, the isolating orseparating step utilizes distillation at any suitable pressure (one ormore than one distillation column can be used).

Additionally or alternatively, the processes disclosed herein canfurther comprise a step of separating at least a portion (and in somecases, all) of the diol compound from the reaction product, and anysuitable technique can be used, such as extraction, filtration,evaporation, distillation, or any combination thereof. Additionally oralternatively, the processes disclosed herein can further comprise astep of separating at least a portion (and in some cases, all) of thereduced chromium catalyst from the reaction product after step (ii), andas above, any suitable technique(s) can be used.

Optionally, certain components of the reaction product—such as theolefin reactant—can be recovered and recycled to the reactor. In suchinstances, the olefin reactant can be recycled and contacted/irradiatedwith supported chromium catalyst again, such that the overall conversionof the olefin reactant is increased after multiple contacts with thesupported chromium catalyst (or multiple passes through the reactorcontaining the supported chromium catalyst).

If desired, the processes disclosed herein can further comprise a stepof (iii) calcining at least a portion (and in some cases, all) of thereduced chromium catalyst to regenerate the supported chromium catalyst.Any suitable calcining conditions can be used, for instance, subjectingthe reduced chromium catalyst to an oxidizing atmosphere at any suitablepeak temperature and time conditions, such as a peak temperature fromabout 300° C. to about 1000° C., from about 500° C. to about 900° C., orfrom about 550° C. to about 870° C., for a time period of from about 1min to about 24 hr, from about 1 hr to about 12 hr, or from about 30 minto about 8 hr.

The calcining step can be conducted using any suitable technique andequipment, whether batch or continuous. For instance, the calcining stepcan be performed in a belt calciner or, alternatively, a rotarycalciner. In some aspects, the calcining step can be performed in abatch or continuous calcination vessel comprising a fluidized bed. Aswould be recognized by those of skill in the art, other suitabletechniques and equipment can be employed for the calcining step, andsuch techniques and equipment are encompassed herein.

An illustrative and non-limiting example of the processes disclosedherein follows for the case in which a C₂-C₈ olefin is the reactant, anda C₂-C₈ diol is the diol product. In this case, the first process forconverting a C₂-C₈ olefin into a C₂-C₈ diol can comprise (i) contactingthe C₂-C₈ olefin and a supported chromium catalyst comprising chromiumin a hexavalent oxidation state to reduce at least a portion of thesupported chromium catalyst to form a reduced chromium catalyst, and(ii) hydrolyzing the reduced chromium catalyst (with any suitablehydrolysis agent) to form a reaction product comprising the C₂-C₈ diolcompound. The second process for converting a C₂-C₈ olefin into a C₂-C₈diol can comprise (i) irradiating the C₂-C₈ olefin and a supportedchromium catalyst comprising chromium in a hexavalent oxidation statewith a light beam at a wavelength in the UV-visible spectrum to reduceat least a portion of the supported chromium catalyst to form a reducedchromium catalyst, and (ii) hydrolyzing the reduced chromium catalyst(with any suitable hydrolysis agent) to form a reaction productcomprising the C₂-C₈ diol.

The C₂-C₈ olefin can comprise ethylene (or propylene, or 1-butene, or1-pentene, or 1-hexene) and the C₂-C₈ diol can comprise ethanediol (orpropanediol, or a butanediol, or a pentanediol, or a hexanediol). Often,the C₂-C₈ diol can comprise a 1,2-diol compound. Moreover, as discussedherein, the process to convert a C₂-C₈ olefin into a C₂-C₈ dioloptionally can further comprise a step of (iii) calcining at least aportion (and in some cases, all) of the reduced chromium catalyst toregenerate the supported chromium catalyst.

Another illustrative and non-limiting example of the processes disclosedherein follows for the case in which a 1-olefin or an α-olefin is thereactant (or a 2-olefin, where the double bond is between the 2nd and3rd carbon atoms), and a 1,2-diol is the diol compound (or a 2,3-diol isthe diol compound). In this case, the first process for converting anα-olefin (or a 2-olefin) into a 1,2-diol (or a 2,3-diol) can comprise(i) contacting the α-olefin (or the 2-olefin) and a supported chromiumcatalyst comprising chromium in a hexavalent oxidation state to reduceat least a portion of the supported chromium catalyst to form a reducedchromium catalyst, and (ii) hydrolyzing the reduced chromium catalyst(with any suitable hydrolysis agent) to form a reaction productcomprising the 1,2-diol compound (or the 2,3-diol compound). The secondprocess for converting an α-olefin (or a 2-olefin) into a 1,2-diol (or a2,3-diol) can comprise (i) irradiating the α-olefin (or the 2-olefin)and a supported chromium catalyst comprising chromium in a hexavalentoxidation state with a light beam at a wavelength in the UV-visiblespectrum to reduce at least a portion of the supported chromium catalystto form a reduced chromium catalyst, and (ii) hydrolyzing the reducedchromium catalyst (with any suitable hydrolysis agent) to form areaction product comprising the 1,2-diol (or the 2,3-diol). For example,if the olefin reactant is 1-hexene, the diol compound can comprise (orconsist essentially of, or consist of) 1,2-hexanediol, while if theolefin reactant is 2-hexene, the diol compound can comprise (or consistessentially of, or consist of) 2,3-hexanediol. Moreover, as discussedherein, these processes can further comprise a step of (iii) calciningat least a portion (and in some cases, all) of the reduced chromiumcatalyst to regenerate the supported chromium catalyst.

Chromium Catalysts

Generally, these disclosed processes are applicable to the reduction ofany hexavalent chromium catalyst, and are not limited to the reductionof any particular type of supported chromium catalyst comprisingchromium in a hexavalent oxidation state. Thus, supported chromiumcatalysts contemplated herein encompass those prepared by contacting asupport with a chromium-containing compound—representative andnon-limiting examples of the chromium-compound compound include chromium(III) acetate, basic chromium (III) acetate, chromium (III)acetylacetonate, Cr₂(SO₄)₃, Cr(NO₃)₃, and CrO₃—and calcining in anoxidizing atmosphere to form a supported chromium catalyst. In theseaspects, chromium can be impregnated during, or prior to, thecalcination step, which can be conducted at a variety of temperaturesand time periods, and can be generally selected to convert all or aportion of the chromium to hexavalent chromium. The methods disclosedherein can comprise reducing at least a portion of the hexavalentchromium species to a reduced oxidation state—for instance, Cr (II)and/or Cr (III) and/or Cr (IV), and/or Cr (V) species, any of which maybe present on the reduced chromium catalyst.

Any suitable chromium-containing compound (or chromium precursor) can beused as a chromium component to prepare the supported chromium catalyst.Illustrative and non-limiting examples of chromium (II) compounds caninclude chromium (II) acetate, chromium (II) chloride, chromium (II)bromide, chromium (II) iodide, chromium (II) sulfate, and the like, aswell as combinations thereof. Likewise, illustrative and non-limitingexamples of chromium (III) compounds can include a chromium (III)carboxylate, a chromium (III) naphthenate, a chromium (III) halide,chromium (III) sulfate, chromium (III) nitrate, a chromium (III)dionate, and the like, as well as combinations thereof. In some aspects,the chromium-containing compound can comprise chromium (III) acetate,chromium (III) acetylacetonate, chromium (III) chloride, chromium (III)bromide, chromium (III) sulfate, chromium (III) nitrate, and the like,as well as combinations thereof.

While not required, it can be beneficial for the chromium-containingcompound to be soluble in a hydrocarbon solvent during preparation ofthe supported chromium catalyst. In such situations, thechromium-containing compound can comprise tertiary butyl chromate, adiarene chromium (0) compound, bis-cyclopentadienyl chromium (II),chromium (III) acetylacetonate, chromium acetate, and the like, or anycombination thereof. Similarly, and not required, it can be beneficialfor the chromium-containing compound to be soluble in water duringpreparation of the supported chromium catalyst. In such situations, thechromium-containing compound can comprise chromium trioxide, chromiumacetate, chromium nitrate, and the like, or any combination thereof.

Various solid supports can be used for the supported chromium catalyst(and the reduced chromium catalyst), such as conventional solid oxidesand zeolites. Generally, the solid oxide can comprise oxygen and one ormore elements selected from Group 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, or 15 of the periodic table, or comprise oxygen and one or moreelements selected from the lanthanide or actinide elements (See:Hawley's Condensed Chemical Dictionary, 11^(th) Ed., John Wiley & Sons,1995; Cotton, F. A., Wilkinson, G., Murillo, C. A., and Bochmann, M.,Advanced Inorganic Chemistry, 6^(th) Ed., Wiley-Interscience, 1999). Forexample, the solid oxide can comprise oxygen and an element, orelements, selected from Al, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn,Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P, Y, Zn, and Zr. Illustrativeexamples of solid oxide materials or compounds that can be used as solidsupport can include, but are not limited to, Al₂O₃, B₂O₃, BeO, Bi₂O₃,CdO, CO₃O₄, Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃, La₂O₃, Mn₂O₃, MoO₃, NiO, P₂O,Sb₂O₅, SiO₂, SnO₂, SrO, ThO₂, TiO₂, V₂O₅, WO₃, Y₂O₃, ZnO, ZrO₂, and thelike, including mixed oxides thereof, and combinations thereof.

The solid oxide can encompass oxide materials such as silica, “mixedoxide” compounds thereof such as silica-titania, and combinations ormixtures of more than one solid oxide material. Mixed oxides such assilica-titania can be single or multiple chemical phases with more thanone metal combined with oxygen to form the solid oxide. Examples ofmixed oxides that can be used as solid oxide include, but are notlimited to, silica-alumina, silica-coated alumina, silica-titania,silica-zirconia, alumina-titania, alumina-zirconia, zinc-aluminate,alumina-boria, silica-boria, aluminum phosphate, aluminophosphate,aluminophosphate-silica, titania-zirconia, and the like, or acombination thereof. In some aspects, the solid support can comprisesilica, silica-alumina, silica-coated alumina, silica-titania,silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria,aluminophosphate-silica, and the like, or any combination thereof.Silica-coated aluminas are encompassed herein; such oxide materials aredescribed in, for example, U.S. Pat. Nos. 7,884,163 and 9,023,959,incorporated herein by reference in their entirety.

The percentage of each oxide in a mixed oxide can vary depending uponthe respective oxide materials. As an example, a silica-alumina (orsilica-coated alumina) typically has an alumina content from 5 wt. % to95 wt. %. According to one aspect, the alumina content of thesilica-alumina (or silica-coated alumina) can be from 5 wt. % alumina 50wt. % alumina, or from 8 wt. % to 30 wt. % alumina. In another aspect,high alumina content silica-aluminas (or silica-coated aluminas) can beemployed, in which the alumina content of these materials typicallyranges from 60 wt. % alumina to 90 wt. % alumina, or from 65 wt. %alumina to 80 wt. % alumina.

In one aspect, the solid oxide can comprise silica-alumina,silica-coated alumina, silica-titania, silica-zirconia, alumina-titania,alumina-zirconia, zinc-aluminate, alumina-boria, silica-boria, aluminumphosphate, aluminophosphate, aluminophosphate-silica, titania-zirconia,or a combination thereof; alternatively, silica-alumina; alternatively,silica-coated alumina; alternatively, silica-titania; alternatively,silica-zirconia; alternatively, alumina-titania; alternatively,alumina-zirconia; alternatively, zinc-aluminate; alternatively,alumina-boria; alternatively, silica-boria; alternatively, aluminumphosphate; alternatively, aluminophosphate; alternatively,aluminophosphate-silica; or alternatively, titania-zirconia.

In another aspect, the solid oxide can comprise silica, alumina,titania, thoria, stania, zirconia, magnesia, boria, zinc oxide, a mixedoxide thereof, or any mixture thereof. In yet another aspect, the solidsupport can comprise silica, alumina, titania, or a combination thereof,alternatively, silica; alternatively, alumina; alternatively, titania;alternatively, zirconia; alternatively, magnesia; alternatively, boria;or alternatively, zinc oxide. In still another aspect, the solid oxidecan comprise silica, alumina, silica-alumina, silica-coated alumina,aluminum phosphate, aluminophosphate, heteropolytungstate, titania,zirconia, magnesia, boria, zinc oxide, silica-titania, silica-yttria,silica-zirconia, alumina-titania, alumina-zirconia, zinc-aluminate,alumina-boria, silica-boria, aluminophosphate-silica, titania-zirconia,and the like, or any combination thereof.

Consistent with certain aspects of this invention, the supportedchromium catalyst and the reduced chromium catalyst can comprise achemically-treated solid oxide as the support, and where thechemically-treated solid oxide comprises a solid oxide (any solid oxidedisclosed herein) treated with an electron-withdrawing anion (anyelectron withdrawing anion disclosed herein). The electron-withdrawingcomponent used to treat the solid oxide can be any component thatincreases the Lewis or Brønsted acidity of the solid oxide upontreatment (as compared to the solid oxide that is not treated with atleast one electron-withdrawing anion). According to one aspect, theelectron-withdrawing component can be an electron-withdrawing anionderived from a salt, an acid, or other compound, such as a volatileorganic compound, that serves as a source or precursor for that anion.Examples of electron-withdrawing anions can include, but are not limitedto, sulfate, bisulfate, fluoride, chloride, bromide, iodide,fluorosulfate, fluoroborate, phosphate, fluorophosphate,trifluoroacetate, triflate, fluorozirconate, fluorotitanate,phospho-tungstate, tungstate, molybdate, and the like, includingmixtures and combinations thereof. In addition, other ionic or non-ioniccompounds that serve as sources for these electron-withdrawing anionsalso can be employed.

It is contemplated that the electron-withdrawing anion can be, or cancomprise, fluoride, chloride, bromide, phosphate, triflate, bisulfate,or sulfate, and the like, or any combination thereof, in some aspectsprovided herein. In other aspects, the electron-withdrawing anion cancomprise sulfate, bisulfate, fluoride, chloride, bromide, iodide,fluorosulfate, fluoroborate, phosphate, fluorophosphate,trifluoroacetate, triflate, fluorozirconate, fluorotitanate, and thelike, or combinations thereof. Yet, in other aspects, theelectron-withdrawing anion can comprise fluoride and/or sulfate.

The chemically-treated solid oxide generally can contain from about 1wt. % to about 30 wt. % of the electron-withdrawing anion, based on theweight of the chemically-treated solid oxide. In particular aspectsprovided herein, the chemically-treated solid oxide can contain fromabout 1 to about 20 wt. %, from about 2 wt. % to about 20 wt. %, fromabout 3 wt. % to about 20 wt. %, from about 2 wt. % to about 15 wt. %,from about 3 wt. % to about 15 wt. %, from about 3 wt. % to about 12 wt.%, or from about 4 wt. % to about 10 wt. %, of the electron-withdrawinganion, based on the total weight of the chemically-treated solid oxide.

In an aspect, the chemically-treated solid oxide can comprise fluoridedalumina, chlorided alumina, bromided alumina, sulfated alumina,fluorided silica-alumina, chlorided silica-alumina, bromidedsilica-alumina, sulfated silica-alumina, fluorided silica-zirconia,chlorided silica-zirconia, bromided silica-zirconia, sulfatedsilica-zirconia, fluorided silica-titania, fluorided silica-coatedalumina, fluorided-chlorided silica-coated alumina, sulfatedsilica-coated alumina, phosphated silica-coated alumina, and the like,as well as any mixture or combination thereof.

In another aspect, the chemically-treated solid oxide employed in thesupported chromium catalyst and the reduced chromium catalyst and theprocesses described herein can be, or can comprise, a fluorided solidoxide and/or a sulfated solid oxide, non-limiting examples of which caninclude fluorided alumina, sulfated alumina, fluorided silica-alumina,sulfated silica-alumina, fluorided silica-zirconia, fluoridedsilica-coated alumina, sulfated silica-coated alumina, and the like, aswell as combinations thereof. Additional information onchemically-treated solid oxide can be found in, for instance, U.S. Pat.Nos. 7,294,599, 7,601,665, 7,884,163, 8,309,485, 8,623,973, and8,703,886, which are incorporated herein by reference in their entirety.

Representative examples of supported chromium catalysts and reducedchromium catalysts (in which a solid oxide is the support) include, butare not limited to, chromium/silica, chromium/silica-titania,chromium/silica-titania-magnesia, chromium/silica-alumina,chromium/silica-coated alumina, chromium/aluminophosphate,chromium/alumina, chromium/alumina borate, and the like, or anycombination thereof. In one aspect, for instance, the supported chromiumcatalyst and the reduced chromium catalyst can comprise chromium/silica,while in another aspect, the supported chromium catalyst and the reducedchromium catalyst can comprise chromium/silica-titania, and in yetanother aspect, the supported chromium catalyst and the reduced chromiumcatalyst can comprise chromium/silica-alumina and/orchromium/silica-coated alumina. In circumstances in which the supportedchromium catalyst and the reduced chromium catalyst comprisechromium/silica-titania, any suitable amount of titanium can be present,including from about 0.1 to about 20 wt. %, from about 0.5 to about 15wt. %, from about 1 to about 10 wt. %, or from about 1 to about 6 wt. %titanium, based on the total weight of the supported chromium catalystand the reduced chromium catalyst.

Representative examples of supported chromium catalysts and reducedchromium catalysts (in which a chemically-treated solid oxide is thesupport) include, but are not limited to, chromium/sulfated alumina,chromium/fluorided alumina, chromium/fluorided silica-alumina,chromium/fluorided silica-coated alumina, and the like, as well ascombinations thereof.

Consistent with certain aspects of this invention, the supportedchromium catalyst and the reduced chromium catalyst can comprise azeolite as the support, i.e., a chromium supported zeolite. Any suitablezeolite can be used, for instance, large pore and medium pore zeolites.Large pore zeolites often have average pore diameters in a range of fromabout 7 Å to about 12 Å, and non-limiting examples of large porezeolites include L-zeolite, Y-zeolite, mordenite, omega zeolite, betazeolite, and the like. Medium pore zeolites often have average porediameters in a range of from about 5 Å to about 7 Å. Combinations ofzeolitic supports can be used.

Additional representative examples of zeolites that can be used in thesupported chromium catalyst and the reduced chromium catalyst include,for instance, a ZSM-5 zeolite, a ZSM-11 zeolite, a EU-1 zeolite, aZSM-23 zeolite, a ZSM-57 zeolite, an ALPO4-11 zeolite, an ALPO4-41zeolite, a Ferrierite framework type zeolite, and the like, or anycombination thereof.

In the supported chromium catalyst and the reduced chromium catalyst,the zeolite can be bound with a support matrix (or binder), non-limitingexamples of which can include silica, alumina, magnesia, boria, titania,zirconia, various clays, and the like, including mixed oxides thereof,as well as mixtures thereof. For example, the supported chromiumcatalyst and the reduced chromium catalyst support can comprise a bindercomprising alumina, silica, a mixed oxide thereof, or a mixture thereof.The zeolite can be bound with the binder using any method known in theart. While not being limited thereto, the supported chromium catalystand the reduced chromium catalyst can comprise a zeolite and from about3 wt. % to about 35 wt. % binder; alternatively, from about 5 wt. % toabout 30 wt. % binder; or alternatively, from about 10 wt. % to about 30wt. % binder. These weight percentages are based on the total weight ofthe supported chromium catalyst or the reduced chromium catalyst.

The amount of chromium in the supported chromium catalyst and thereduced chromium catalyst also is not particularly limited. However, theamount of chromium in the supported chromium catalyst and the reducedchromium catalyst typically ranges from about 0.01 to about 50 wt. %;alternatively, from about 0.01 to about 20 wt. %; alternatively, fromabout 0.01 to about 10 wt. %; alternatively, from about 0.05 to about 15wt. %; alternatively, from about 0.1 to about 15 wt. %; alternatively,from about 0.2 to about 10 wt. %; alternatively, from about 0.1 to about5 wt. %; alternatively, from about 0.5 to about 30 wt. %; oralternatively, from about 0.5 to about 2.5 wt. %. These weightpercentages are based on the amount of chromium relative to the totalweight of the supported chromium catalyst or the reduced chromiumcatalyst. While not wishing to be bound by theory, it is believed thatlower chromium loadings (e.g., 1 wt. % and less) can result in higherselectivity to a particular diol compound, while higher chromiumloadings (e.g., 5-15 wt. % and above) can result in higher diol yieldsper gram of catalyst.

Likewise, the amount of chromium in an average oxidation state of +5 orless in the reduced chromium catalyst is not particularly limited, andcan fall within the same ranges. Thus, the reduced chromium catalyst cancontain from about 0.01 to about 50 wt. %, from about 0.01 to about 20wt. %, from about 0.01 to about 10 wt. %, from about 0.05 to about 15wt. %, from about 0.1 to about 15 wt. %, from about 0.2 to about 10 wt.%, from about 0.1 to about 5 wt. %, from about 0.5 to about 30 wt. %, orfrom about 0.5 to about 2.5 wt. % of chromium in an average oxidationstate of +5 or less, based on the total weight of the reduced chromiumcatalyst.

Generally, at least about 10 wt. % of the chromium in the supportedchromium catalyst is present in a hexavalent oxidation state before thereduction step, and more often at least about 20 wt. % is present aschromium (VI). In further aspects, at least about 40 wt. %, at leastabout 60 wt. %, at least about 80 wt. %, at least about 90 wt. %, or atleast about 95 wt. %, of the chromium in the supported chromium catalystcan be present in an oxidation state of +6. These weight percentages arebased on the total amount of chromium. Traditional chromium (VI)catalysts often will have an orange, yellow, or tan color, indicatingthe presence of chromium (VI).

Conversely, less than or equal to about 50 wt. % of the chromium in thereduced chromium catalyst is typically present in an oxidation state of+6 (VI), and more often less than or equal to about 40 wt. %. In furtheraspects, less than or equal to about 30 wt. %, or less than or equal toabout 15 wt. % of chromium in the reduced chromium catalyst can bepresent in an oxidation state of +6. The minimum amount of chromium (VI)often can be 0 wt. % (no measurable amount), at least about 0.5 wt. %,at least about 1 wt. %, at least about 2 wt. %, or at least about 5 wt.%. These weight percentages are based on the total amount of chromium.The reduced chromium catalysts often will have a green, blue, gray, orblack color.

Thus, the contacting (optionally, with irradiation) of the supportedchromium catalyst with the olefin reactant ordinarily results in atleast about 10 wt. %, at least about 20 wt. %, at least about 40 wt. %,at least about 60 wt. %, at least about 80 wt. %, or at least about 90wt. %, of the supported chromium catalyst being reduced or converted toform the reduced chromium catalyst.

Additionally or alternatively, the chromium in the reduced chromiumcatalyst can be characterized by an average valence of less than orequal to about 5.25. More often, the chromium in the reduced chromiumcatalyst has an average valence of less than or equal to about 5;alternatively, an average valence of less than or equal to about 4.75;alternatively, an average valence of less than or equal to about 4.5;alternatively, an average valence of less than or equal to about 4.25;or alternatively, an average valence of less than or equal to about 4.

The total pore volume of the supported chromium catalyst and the reducedchromium catalyst is not particularly limited, and high pore volume isnot required for the disclosed processes. For instance, the supportedchromium catalyst and the reduced chromium catalyst can have a totalpore volume in a range from about 0.1 to about 5 mL/g, from about 0.15to about 5 mL/g, from about 0.1 to about 3 mL/g, from about 0.5 to about2.5 mL/g, or from about 0.15 to about 2 mL/g. Likewise, the surface areaof the supported chromium catalyst and the reduced chromium catalyst isnot limited to any particular range. Generally, however, the supportedchromium catalyst and the reduced chromium catalyst can have a BETsurface area in a range from about 50 to about 2000 m²/g, from about 50to about 700 m²/g, from about 50 to about 400 m²/g, from about 100 toabout 1200 m²/g, from about 150 to about 525 m²/g, or from about 300 toabout 1000 m²/g.

The supported chromium catalyst and the reduced chromium catalyst canhave any suitable shape or form, and such can depend on the type ofprocess that is employed to convert the olefin reactant into the diolcompound (e.g., fixed bed versus fluidized bed). Illustrative andnon-limiting shapes and forms include powder, round or spherical (e.g.,a sphere), ellipsoidal, pellet, bead, cylinder, granule (e.g., regularand/or irregular), trilobe, quadrilobe, ring, wagon wheel, monolith, andthe like, as well as any combination thereof. Accordingly, variousmethods can be utilized to prepare the supported chromium catalystparticles, including, for example, extrusion, spray drying, pelletizing,marumerizing, spherodizing, agglomeration, oil drop, and the like, aswell as combinations thereof.

In some aspects, the supported chromium catalyst and the reducedchromium catalyst have a relatively small particle size, in whichrepresentative ranges for the average (d50) particle size of thesupported chromium catalyst and the reduced chromium catalyst caninclude from about 10 to about 500 microns, from about 25 to about 250microns, from about 20 to about 100 microns, from about 40 to about 160microns, or from about 40 to about 120 microns.

In other aspects, the supported chromium catalyst and the reducedchromium catalyst can be in the form of pellets or beads—and thelike—having an average size ranging from about 1/16 inch to about ½inch, or from about ⅛ inch to about ¼ inch. As noted above, the size ofthe supported chromium catalyst and/or reduced chromium catalystparticles can be varied to suit the particular process for convertingthe olefin reactant into the diol.

Examples 1-67

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, modifications, and equivalentsthereof, which after reading the description herein, can suggestthemselves to one of ordinary skill in the art without departing fromthe spirit of the present invention or the scope of the appended claims.

Catalyst A was a Cr/silica catalyst containing 1 wt. % Cr, with a BETsurface area of 500 m²/g, a pore volume of 1.6 mL/g, and an averageparticle size of 100 μm. Prior to use, the catalyst was calcined in airat 650° C. for 3 hr to form the chromium (VI)/silica catalyst containing0.97 wt. % hexavalent Cr.

Catalyst B was a Cr/silica-titania catalyst containing 1 wt. % Cr and4.2 wt. % TiO₂, with a BET surface area of 500 m²/g, a pore volume of2.5 mL/g, and an average particle size of 130 μm. Prior to use, thecatalyst was calcined in air at 850-870° C. for 3 hr to form thechromium (VI)/silica-titania catalyst containing 0.95 wt. % hexavalentCr.

Catalyst C was a Cr/silica containing 10 wt. % Cr, the silica having aBET surface area of 500 m²/g, a pore volume of 1.6 mL/g, and an averageparticle size of 100 μm. Prior to use, the catalyst was calcined in airat 400° C. for 3 hr to form the chromium (VI)/silica catalyst containing5 wt. % hexavalent Cr.

Catalyst D was a Cr/silica-titania containing 0.8 wt. % Cr and 7.5 wt. %TiO₂, with a BET surface area of 550 m²/g, a pore volume of 2.5 mL/g,and an average particle size of 130 μm. Prior to use, the catalyst wascalcined in air at 850° C. for 3 hr to form the chromium(VI)/silica-titania catalyst containing 0.8 wt. % hexavalent Cr.

Catalyst E was a Cr/silica containing 0.28 wt. % Cr, with a BET surfacearea of 500 m²/g, a pore volume of 1.6 mL/g, and an average particlesize of 100 μm. Prior to use, the catalyst was calcined in air at 750°C. for 3 hr to form the chromium (VI)/silica catalyst containing 0.28wt. % hexavalent Cr.

Catalyst F was a Cr/silica containing 5 wt. % Cr, with a BET surfacearea of 500 m²/g, a pore volume of 1.6 mL/g, and an average particlesize of 100 μm. Prior to use, the catalyst was calcined in air at 500°C. for 3 hr to form the chromium (VI)/silica catalyst containing 4 wt. %hexavalent Cr.

Catalysts G1-G2 were prepared by dissolving CrO₃ in water, thenimpregnating the resulting solution onto an alumina (boehmite) with aBET surface area of 300 m²/g and a pore volume of 1.3 mL/g to equal 5wt. % Cr. After drying and prior to use, the catalysts were calcined inair at 500° C. (G1) or 600° C. (G2) for 3 hr to form the chromium(VI)/alumina catalysts containing 4.5 wt. % hexavalent Cr.

Catalysts H1-H2 were prepared by dissolving CrO₃ in water, thenimpregnating the resulting solution onto a silica-coated alumina (40 wt.% silica, BET surface area of 450 m²/g, pore volume of 1.4 mL/g, averageparticle size of 25 μm) to equal 5 wt. % Cr. After drying and prior touse, the catalysts were calcined in air at 500° C. (H1) or 600° C. (H2)for 3 hr to form the chromium (VI)/silica-coated alumina catalysts.

Catalyst J was prepared by dissolving K₂Cr₂O₇ in water, thenimpregnating the resulting solution onto a silica (BET surface area of500 m²/g, pore volume of 1.6 mL/g, average particle size of 100 μm) toequal 5 wt. % Cr. After drying and prior to use, the catalyst wascalcined in air at 500° C. for 3 hr to form the chromium (VI)/silicacatalyst containing 5 wt. % hexavalent Cr.

Catalyst K was prepared by dissolving K₂Cr₂O₇ in water, thenimpregnating the resulting solution onto a silica (BET surface area of500 m²/g, pore volume of 1.6 mL/g, average particle size of 100 μm) toequal 10 wt. % Cr. After removing excess water, the catalyst was heattreated in air at 100° C. for 3 hr to form the chromium (VI)/silicacatalyst containing 10 wt. % hexavalent Cr.

Catalyst L was prepared by dissolving K₂Cr₂O₇ in water, thenimpregnating the resulting solution onto a silica (BET surface area of500 m²/g, pore volume of 1.6 mL/g, average particle size of 100 μm) toequal 10 wt. % Cr. After removing excess water, the catalyst was heattreated in air at 200° C. for 3 hr to form the chromium (VI)/silicacatalyst containing 10 wt. % hexavalent Cr.

BET surface areas can be determined using the BET nitrogen adsorptionmethod of Brunauer et al., J. Am. Chem. Soc., 60, 309 (1938) asdescribed in ASTM D1993-91. Total pore volumes can be determined inaccordance with Halsey, G. D., J. Chem. Phys. (1948), 16, pp. 931. Thed50 particle size, or median or average particle size, refers to theparticle size for which 50% of the sample by volume has a smaller sizeand 50% of the sample has a larger size, and can be determined usinglaser diffraction in accordance with ISO 13320.

Table I summarizes the reactions of Examples 1-67, in which thesupported chromium catalyst was first charged to an air-tight glasscontainer at 25° C. (or a different temperature if specified), followedby the addition of the hydrocarbon reactant. The glass container wasthen exposed to a light source as noted in Table I. For all exampleswhere the glass container was exposed to light, the container was slowlyrotated at 5-10 rpm to turn over the catalyst particles in the bottle toensure even exposure of the mixture of the supported chromium catalystand the hydrocarbon reactant to each other and to the light. Samplesexposed to sunlight were taken outside and placed in direct sunlight.For examples where the glass container was exposed to artificial light,the sample was placed in a box containing a fluorescent light or a LEDlight, where three 15 watt bulbs were placed in a plane about 3 inchesapart and about 2 inches from the bottle. Reduction of the supportedchromium catalysts was monitored by the presence of a color change. Eachsupported chromium catalyst comprising chromium in the hexavalentoxidation state had an orange color which darkened significantly uponexposing the supported chromium catalyst to light in the presence of thehydrocarbon reactant, and usually assuming a green or blue color,indicating reduction of the supported chromium catalyst startingmaterial, and formation of the reduced chromium catalyst.

After the desired exposure time, the reduced chromium catalyst was mixedwith a hydrolysis agent to cleave the hydrocarbon-containing ligand fromthe reduced chromium catalyst. The mixture was stirred for severalminutes. The hydrolysis agent used was generally selected so as to notinterfere with analysis of the reaction product (e.g., methanol was notused as the hydrolysis agent when the reaction product after hydrolysiscould contain methanol, etc.).

Table I summarizes the results of Examples 1-67, and lists the specificsupported chromium catalyst and amount, the hydrocarbon reactant andamount, the light treatment and resulting color, the hydrolysis agentand amount, the acid/Cr (molar), alcohol/Cr (molar), the GC-MS/Cr(molar), the total/Cr (molar), and an analysis of the reaction product(oxygenated products) after hydrolysis. The reaction product analysisincludes only oxygen-containing products that were derivable from thereductant/reactant and does not include, for example, materialsresulting from the hydrolysis agent or its by-products, or oligomersresulting from polymerization. For the oxygenated reaction products,area % from the analytical procedures listed below is roughly equivalentto mol %, thus the results in Table I are shown in mol %.

Carboxylic acid products (and acid/Cr ratios on a molar basis) weredetermined by first neutralizing the product acids with a solution ofsodium hydroxide to put them into the ionic form. Then, a small amountof the sample was injected through an ion column designed to separateanions from weak organic acids through an ion chromatography process. ADionex IC-3000 instrument with an ICE-AS1 column and guard was used. Thetest was specifically sensitive to linear carboxylic acids from C₁ toC₆, glutarate and glycolate ions. Results were reported in micrograms ofcarboxylate per mL of solution, which was then converted to moles.

Lower alcohol products (and alcohol/Cr on a molar basis) were determinedusing a GC-MS procedure, with an Agilent 6890 gas chromatograph having aflame-ionizing detector (FID). It used a Restek Stapilwax column (P/N10658) designed and gated specifically to separate and detect lightalcohols. The procedure was gated for acetone, methanol, ethanol,isopropanol, n-propanol, isobutanol, n-butanol, t-butanol, 2-butanol,2-butoxyethanol, acetonitrile and tetrahydrofuran.

Additional reaction products (and GC-MS/Cr on a molar basis) weredetermined using another GC-MS procedure, as follows. Gas chromatographywas performed using an Agilent 7890B GC equipped with both flameionizing and mass spectral analysis. An all-purpose capillary column(Agilent J&W VF-5 ms, 30 m×0.25 mm×0.25 μm) was used with variabletemperature. Approximate 0.5 μL sample aliquots were injected into a GCport held at 250° C. using a split ratio of 10:1. The carrier gas wasultra-high purity helium and was electronically controlled throughoutthe run to a constant flow rate of 1.2 mL/min. Initial columntemperature was held at 50° C. for 5 min, ramped at 20° C./min to 250°C., and then held at 250° C. for 19 min. Spectral assignment was madevia mass correlation using an Agilent 5977B mass spectrometer connectedto the GC unit using electron ionization at 70 eV. The nominal massrange scanned was 14-400 m/z using a scan time of 0.5 sec. Nominaldetector voltage used was 1200 V. For calibration purposes both the FIDand MS detectors were sometimes used in sequence on the same orreference samples.

Due to the wide range of oxygenated products produced herein, one or allof these three procedures were used to characterize the reaction productafter hydrolysis. In some cases, the same compound was detected by morethan one technique, and this was subtracted out of the total/Cr (on amolar basis) to prevent double counting of the same compound by morethan one analytical technique. For the most part, however, there wasvery little overlap between the three analytical procedures.

Referring now to the data in Table I, Examples 1-10 demonstrate theunexpected conversion of methane into methanol at ambient temperatureusing a variety of supported chromium catalysts, irradiation treatments,and hydrolysis agents. Note that Examples 1-4 used only one analyticaltechnique and showed a product stream that was 100% methanol, whereasExamples 6-10 used all three analytical techniques and resulted inproduct streams containing 66-97 mol % methanol, the balance beingformic acid.

Similar successful results were found for the conversion of ethane intoethanol, isobutane into t-butanol/i-butanol, n-pentane into2-pentanol/1-pentanol, cyclopentane into cyclopentanol, n-hexane intovarious hexanols, cyclohexane into cyclohexanol, and toluene intobenzaldehyde/benzyl alcohol. When the hydrocarbon reactant wasi-pentane, the oxygenated reaction product contained a variety ofalcohol and carbonyl products, whereas when the reactant wasdichloromethane, no conversion to an alcohol or carbonyl was noted.While the focus of these examples was not to maximize chromiumconversion (or yield to any particular alcohol or carbonyl compound),the total/Cr molar value in Table I illustrates that significantchromium conversion and alcohol/carbonyl yield can be achieved,depending of course on the reductant, the catalyst (and chromiumloading), and the irradiation conditions, among other factors.

When the reactant was an olefin, it was found that the GC-MS analyticaltechnique was necessary to identify diol products, thus examples inwhich this technique was not used may give an incomplete representationof the oxygenated product mix. Generally, examples that utilizedethylene as the reductant formed a reaction product (even when used at−78° C. to prevent polymerization) after hydrolysis that includedethanediol and methanol, ethanol, formic acid, and/or acetic acid. Thelower reaction temperatures seemed to favor selectivity to the diol.Examples that utilized 1-pentene as the reductant formed a reactionproduct (even with no light irradiation, see Example 44) afterhydrolysis that included a pentanediol (e.g., 1,2-pentanediol) andvarious acids and other alcohols (e.g., formic acid and butanol).Examples that utilized 1-hexene or 2-hexene as the reductant formed areaction product (even with no light irradiation, see Example 55) afterhydrolysis that included a hexanediol (e.g., 1,2-hexanediol and/or2,3-hexanediol and/or 3,4-hexanediol) and various acids and otheralcohols. Table I demonstrates that these olefins are very reactive and,therefore, the reaction product typically contained a mixture ofmono-alcohols, diols, aldehydes, ketones, and/or carboxylic acids.

TABLE I Summary of Examples 1-67 (products in mol %) Example 1 2 3 4Catalyst A B A B Weight (g) 2.7 2.0 1.8 2.0 Reductant Methane MethaneMethane Methane Amount 10 psig 10 psig 10 psig 10 psig Light 4 hr Sun 4hr Sun 6 hr Sun 6 hr Sun Color Green Green Green Green HydrolysisH₂O/Ether H₂O/Ether H₂O H₂O Amount (mL) 20 20 20 20 Acid/Cr 0 0 0Alcohol/Cr 1.013 0.272 0.261 0.173 GC-MS/Cr Total/Cr 1.013 0.272 0.2610.173 Oxygenated methanol 100% methanol 100% methanol 100% methanol 100%Products Example 5 6 7 8 Catalyst D E J F Weight (g) 2.1 2.8 2.2 2.1Reductant Methane Methane Methane Methane Amount 15 psig 15 psig 15 psig15 psig Light 44 hr Blue 67 hr Blue 67 hr Blue 67 hr Blue Color Olivegreen Olive green Red-brown Dark brown-black Hydrolysis H₂O + CH₃CNH₂O + CH₃CN H₂O + CH₃CN H₂O + CH₃CN Amount (mL) 15 15 15 15 Acid/Cr0.009 0.010 0.007 0.008 Alcohol/Cr 0.284 0.320 0.030 0.073 GC-MS/Cr0.007 0.000 0 0.0025 Total/Cr 0.300 0.330 0.037 0.081 Oxygenatedmethanol 96% methanol 97% methanol 80% methanol 90% Products formic acid 4% formic acid  3% formic acid 20% formic acid 10% Example 9 10 11 12Catalyst H2 G2 D B Weight (g) 2.2 2.0 2.0 2.1 Reductant Methane MethaneDichloromethane Ethane Amount 15 psig 15 psig 0.5 mL 15 psig Light 67 hrBlue 67 hr Blue 7 hr Blue 72 hr Blue Color Dark brown Dark brown OliveGreen Blue-gray Hydrolysis H₂O + CH₃CN H₂O + CH₃CN 10% H₂O/MeOH H₂OAmount (mL) 15 15 40 20 Acid/Cr 0.003 0.002 0.042 Alcohol/Cr 0.025 0.0040.366 GC-MS/Cr 0.000 0.000 0.000 0.000 Total/Cr 0.028 0.006 0.000 0.408Oxygenated methanol 91% methanol 66% No Products ethanol 72% Productsformic acid  9% formic acid 34% Detected methanol 16% formic acid  6%hexanoic acid  3% acetic acid  1% pentanoic acid  1% Example 13 14 15 16Catalyst D D B B Weight (g) 1.9 2.5 2.6 1.9 Reductant Ethane i-Butanen-Pentane n-Pentane Amount 15 psig 10 psig 0.75 mL 0.75 mL Light 30 hrBlue 6 hr UV 1 hr UV 3.3 hr UV Color Blue-gray Green Blue-gray Blue-grayHydrolysis H₂O + CH₃CN 4% H₂O/MeOH 10% H₂O/MeOH 10% H₂O/MeOH Amount (mL)15 15 12 12 Acid/Cr 0.013 0.000 Alcohol/Cr 0.374 0.258 GC-MS/Cr 0.0090.465 0.270 0.500 Total/Cr 0.383 0.723 0.270 0.500 Oxygenated ethanol90% t-butanol 40% 2-pentanol 49% 2-pentanol 47% Products methanol  6%i-butanol 29% 2-pentanone 33% 2-pentanone 36% acetic acid  3% acetone10% 1-pentanol 18% 1-pentanol 17% isopropanol  1% isopropanol  5%n-propanol  1% isobutanal  5% Example 17 18 19 20 Catalyst C D E DWeight (g) 1.9 2.0 2.6 2.0 Reductant n-Pentane n-Pentane n-Pentanen-Pentane Amount 0.5 mL 0.5 mL 2 mL 2 mL Light 3 hr Blue 7 hr Blue 26 hrUV 26 hr UV Color Black Blue-gray Blue-gray Blue-gray Hydrolysis 10%H₂O/MeOH Vitamin C 5% H₂O/MeOH 5% H₂O/MeOH Amount (mL) 11 30 10 10Acid/Cr 0.000 0.000 0.000 0.042 Alcohol/Cr 0.000 0.000 GC-MS/Cr 0.2071.140 0.143 0.499 Total/Cr 0.207 1.140 0.143 0.541 Oxygenated2-pentanone 62% 2-pentanol 63% 2-pentanol 41% 2-pentanol 39% Products2-pentanol 14% 1-pentanol 19% 1-pentanol 23% 1-pentanol 21% 3-pentanone10% pentanal 18% 2-pentanone 21% 2-pentanone 15% 3-penten-2-one  3%3-pentanone 11% 3-pentanone 10% 1-pentanol  2% C10H18O  4% formic acid 8% 3-penten-2-one  2% 2-pentenal  2% Example 21 22 23 24 Catalyst L D ED Weight (g) 3.0 1.9 2.3 1.1 Reductant n-Pentane i-Pentane i-Pentanei-Pentane Amount 2 mL 0.5 mL 0.5 mL 2 mL Light UV 24 h 7 hr Blue 31 hrBlue 4.5 hr UV Color Brown Blue-gray Blue-gray Gray-blue Hydrolysis 4%H₂O/MeOH 10% H₂O/MeOH H₂O + CH₃CN 5% H₂O/MeOH Amount (mL) 15 40 15 15Acid/Cr 0.002 0.000 0.000 0.006 Alcohol/Cr 0.005 0.347 GC-MS/Cr 0.0770.850 0.929 0.600 Total/Cr 0.083 0.850 0.929 0.953 Oxygenated 2-pentanol40% t-pentanol 24% 2-pentanol 31% ethanol 27% Products 2-pentanone 21%3-Me-2-butanol 23% acetic acid 23% 2-Me-1-butanol 18% 1-pentanol 15%Me-butanol 22% 2-pentanol 22% t-pentanol 17% 3-pentanone  9% isoamylalcohol 13% 3-pentanol 11% 3-Me-2-butanol 10% isopropanol  4%2-Me-butanal 11% C5H4O3  7% isoamyl alcohol  9% C10H18O  2%3-Me-2-butanone  7% isobutanol  8% C7H14O  2% 3-Me-2-butanone  6% formicacid  2% C6H12O3  3% Example 25 26 27 28 Catalyst J F H1 G1 Weight (g)2.2 2.4 1.9 1.9 Reductant i-Pentane i-Pentane i-Pentane i-Pentane Amount0.5 mL 0.5 mL 0.5 mL 0.5 Light 31 hr Blue 31 hr Blue 40 hr Blue 40 hrBlue Color Dark red Blue-gray-black Green-brown Green-brown HydrolysisH₂O + CH₃CN H₂O + CH₃CN H₂O + CH₃CN H₂O + CH₃CN Amount (mL) 15 15 15 15Acid/Cr 0.004 0.004 0.004 0.016 Alcohol/Cr GC-MS/Cr 0.744 0.042 0.0610.052 Total/Cr 0.747 0.046 0.064 0.068 Oxygenated 2-Me-2-butanol 41%3-Me-1-butanol 26% C5H12O alcohol 25% C5H12O 23% Products 3-Me-2-butanol21% 2-Me-1-butanol 24% C5H8O aldehyde 22% 2-Me-2-butenal 23%2-Me-1-butanol 15% 2-Me-2-butenal 24% C5H12O 17% C5H12O2 13%3-Me-2-butanone  9% 3-Me-2-butenal  5% 3-Me-2-pentanone  5% formic acid12% 3-Me-1-butanol  9% acetic acid  4% C5H12O2  5% C5H12O 12% C10/C11 2% C5H10O2  4% C6H10O  4% acetic acid 11% dioxygenate formic acid  4%4-OH-3-Me-2-  3% 2-pentenal  2% butanone formic acid  3% C5H10O  3%3-Me-2 butenal  2% acetic acid  2% Example 29 30 31 32 Catalyst D B B BWeight (g) 2.1 2.1 1.2 1.5 Reductant Cyclopentane n-Hexane CyclohexaneDecalin Amount 0.5 mL 0.5 mL 0.5 g Light 7 hr Blue 3.3 hr UV 2 hr BlueLED 2 hr Blue LED Color Blue-gray Blue-gray Deep blue Light blueHydrolysis 10% H₂O/MeOH 10% H₂O/MeOH 10% H₂O/MeOH 10% H₂O/MeOH Amount(mL) 40 12 12 12 Acid/Cr 0.000 No data No data Alcohol/Cr No data Nodata GC-MS/Cr 0.606 0.573 No data No data Total/Cr 0.606 0.573Oxygenated cyclopentanol 85% 2-hexanol 25% cyclohexanol 49% decalols,17% Products cyclopentanone 15% 2-hexanone 23% cyclohexanone 40% C10H18O3-hexanol 20% 2-cyclohexen-1-  7% decalones, 16% 3-hexanone 17% oneC10H18O 1-hexanol 15% cyclohexanediol  2% C10H14O  2% C14H22O  1%C10H14O2  1% C6H10O2  1% naphthalenone  1% Example 33 34 35 36 CatalystB B K A Weight (g) 1.1 1.6 3.3 2.0 Reductant Adamantane Toluene TolueneEthylene Amount 0.5 g 0.5 mL 2 mL 10 psig Light 2 hr Blue LED 1.5 hrBlue UV 24 h 9 hr Sun Color Blue Blue-black Brown Blue-gray Hydrolysis10% H₂O/MeOH 10% H₂O/MeOH 4% H₂O/MeOH H₂O Amount (mL) 12 6 15 20 Acid/CrNo data 0.001 0.096 Alcohol/Cr No data 0.003 0.108 GC-MS/Cr No data0.567 0.129 Total/Cr 0.567 0.133 0.204 Oxygenated adamantone 32%benzaldehyde 41% benzaldehyde 77% methanol 51% Products adamantol 25%benzyl alcohol 17% benzyl alcohol 20% formic acid 46% adamantan-2-ol 20%C14H12O  9% isopropanol  2% n-propanol  2% C10H14O 16% benzophenone  8%formic acid  1% acetic acid  1% adamantanediol  2% C14H12O  6% C11H20O 1% C14H12O  6% 4-Me phenol  5% 2-Me phenol  5% Example 37 38 39 40Catalyst B D D D Weight (g) 2.1 2.4 2.1 2.1 Reductant Ethylene EthyleneEthylene Ethylene Amount 10 psig 15 psig (−78 C.) 15 psig (−78 C.) 15psig (−78 C.) Light 9 hr Sun 60 hr Blue 24 hr Blue 24 hr Blue ColorBlue-gray Blue-green Blue-green Blue-green Hydrolysis 0.1N NaOH 0.1NNaOH 0.1N NaOH 0.1N NaOH Amount (mL) 20 15 15 15 Acid/Cr 0.233 0.1100.136 0.144 Alcohol/Cr 0.101 0.162 0.111 0.401 GC-MS/Cr 0.035 0.0710.162 Total/Cr 0.335 0.272 0.318 0.675 Oxygenated formic acid 68% formicacid 39% formic acid 48% ethanediol 72% Products methanol 28% methanol29% ethanediol 25% formic acid 20% acetic acid  1% ethanediol 27%methanol 24% diethylene glycol  4%  1% ethanol  2% ethanol  2% methanol 2% acetic acid  1% n-propanol  1% acetic acid  1% n-propanol  1%propionic acid  1% ethanol  1% acetic acid  1% Example 41 42 43 44Catalyst E D D D Weight (g) 2.3 2.0 1.5 2.1 Reductant Ethylene Ethylene1-Pentene 1-Pentene Amount 15 psig 15 psig 0.5 mL 0.5 mL Light 24 hr UV24 hr UV 14 hr Blue Dark-24 hr Color Blue-gray Hydrolysis H₂O + CH₃CNH₂O + CH₃CN H₂O H₂O Amount (mL) 15 15 20 15 Acid/Cr 0.461 0.181 0.2450.012 Alcohol/Cr 0.136 0.069 0.044 GC-MS/Cr 0.017 0.190 1.047 0.016Total/Cr 0.614 0.436 1.193 0.072 Oxygenated acetic acid 38% formic acid35% C8H18O 17% 1-butanol 29% Products formic acid 36% ethanediol 32%formic acid 13% formic acid 14% methanol 19% methanol 12% C10 or C11alcohol 12% n-propanol  9% ethanediol  2% diethylene glycol 11%1,2-pentanediol  7% ethanediol  8% ethanol  2% acetic acid  6% C9H20O 7% 1,2-pentandiol  8% n-propanol  1% ethanol  3% C8-C10 alcohol  6%methanol  8% 2-heptanone  5% 2-pentenal  7% C7H14O3  4% acetone  5%C10H22O  4% 2-penten-1-ol  3% isoamyl alcohol  3% ethanol  2% aceticacid  3% 3-pentanol  2% Example 45 46 47 48 Catalyst D D D D Weight (g)2.0 1.9 1.7 1.5 Reductant 1-Pentene 1-Pentene 1-Hexene 1-Hexene Amount0.5 mL 0.5 mL 0.5 mL 0.5 mL Light 24 hr UV 2 hr UV 7 hr Blue 14 hr BlueColor Magenta Sky blue Blue-gray Blue-gray Hydrolysis H₂O H₂O 10%H₂O/MeOH H₂O Amount (mL) 15 15 40 20 Acid/Cr 0.015 0.018 0.036 0.248Alcohol/Cr 0.000 0.091 GC-MS/Cr 0.087 0.124 1.315 Total/Cr 0.102 0.2330.036 1.548 Oxygenated 1,2-pentanediol 31% 1-butanol 20% formic acid100% hexanoic acid 41% Products 2-pentenal 13% 1,2-pentanediol 17%formic acid 10% formic acid 11% 2-pentenal 11% 2-hexanone  8% C10H22O10% n-propanol  7% 2-octanone  3% C5H10O2  5% ethanediol  7%1,2-hexanediol  3% 2-heptanone  5% formic acid  6% 1-hexen-3-ol  3%C8-11 oxygenate  3% ethyl ether  5% 3-penten-2-ol  3% C8-10 oxygenate 3% propanoic acid Me-nonanol  2% C9-11 oxygenate  3% 2-penten-1-ol  5%Me-heptanol  2% C5 di-oxygenate  2% ethanol  3% butyric acid  2% C10H20O 2% 2-heptanone  2% 2-hexanol  2% methanol  2% 2-hexenal  2%2-Me-2-pentenal  2% Example 49 50 51 52 Catalyst D D D D Weight (g) 2.12.1 2.0 1.2 Reductant 1-Hexene 1-Hexene 1-Hexene 1-Hexene Amount 0.5 mL0.5 mL 0.5 mL 2 mL Light 14 hr Blue 31 hr Blue 31 hr Blue 4.5 hr UVColor Blue-gray Blue-gray Blue-gray Blue-green Hydrolysis Vitamin CH₂O + CH₃CN 0.1N HCl + Fe⁺² 5% H₂O/MeOH Amount (mL) 20 15 15 15 Acid/Cr0.058 0.082 0.038 0.007 Alcohol/Cr 0.198 GC-MS/Cr 0.426 0.153 0.0950.458 Total/Cr 0.426 0.235 0.133 0.663 Oxygenated 1-hexene-3-ol 19%formic acid 35% formic acid 28% ethanol 22% Products hexanoic acid 14%1-hexen-3-ol 18% 1-hexen-3-ol 24% 2-hexen-1-ol 15% 1,2-hexanediol 14%1,2-hexanediol 12% 1,2-hexanediol 18% 1-hexen-3-ol 13% C6 oxygenate 10%C6H14O2-Si  8% C6H12O  9% 3-hexanone 11% formic acid  9% 2-hexenal  6%2-hexenal  9% 2-hexenal 10% 2-hexen-1-ol  7% dimethylbutanol  4%2-hexen-1-ol  7% 2-hexanol  9% C5/C6 oxygenate  6% 2-hexene-1-ol  4%2-hexanol  5% n-propanol  7% acetic acid  5% 2-octanone  3% 2-hexanone 6% 2-hexnaone  2% 1,2-hexanediol  5% hexanal  2% C6H12O  2% 2-hexanol 2% Example 53 54 55 56 Catalyst E D D D Weight (g) 2.0 1.6 2.2 2.0Reductant 1-Hexene 1-Hexene 1-Hexene 1-Hexene Amount 0.5 mL 0.5 mL 0.5mL 0.5 mL Light 24 hr UV 2 hr UV Dark-24 hr 24 hr UV Color Blue-grayMagenta Hydrolysis H₂O + CH₃CN H₂O H₂O H₂O Amount (mL) 15 10 15 15Acid/Cr 0.127 0.011 0.011 0.011 Alcohol/Cr 0.069 0.021 0.010 0.013GC-MS/Cr 0.012 0.040 0.163 0.134 Total/Cr 0.208 0.072 0.184 0.159Oxygenated acetic acid 58% 1.2-hexanediol 26% 1-hexen-3-ol 28%1-hexen-3-ol 19% Products methanol 13% formic acid 15% 2-hexenal 17%1,2-hexanediol 15% ethanol 10% ethanol 14% 1,2-hexanediol 13% 2-hexenal12% 1-butanol  7% isobutanol 12% C6H12O  8% 2-hexanone  9%1,2-hexanediol  6% C6H14O  7% C6H12O  7% 2-hexen-1-ol  6% formic acid 4% C9/C10 oxygenate  6% 2-hexen-1-ol  6% formic acid  6% n-propanol  3%1-hexanol  3% formic acid  5% C6H12O  5% 1-butanol  3% dimethylbutanoic 5% C6H12O2  4% 1-pentanol  2% acid hexenal  4% 2-hexanone  2% 1-butanol 3% 1-butanol  4% 3-Me-2-pentanone  2% C6H14O  3% 2-hexanol  3% Example57 58 59 60 Catalyst D J F H1 Weight (g) 2.0 2.6 2.8 1.9 Reductant1-Hexene 1-Hexene 1-Hexene 1-Hexene Amount 0.5 mL 0.5 mL 0.5 mL 0.5 mLLight 2 hr UV 31 hr Blue 31 hr Blue 40 hr Blue Color Sky blue Dark redBlue-gray-black Green-brown Hydrolysis H₂O H₂O + CH₃CN H₂O + CH₃CN H₂O +CH₃CN Amount (mL) 15 15 15 15 Acid/Cr 0.012 0.010 0.001 0.003 Alcohol/Cr0.014 GC-MS/Cr 0.102 0.496 0.794 0.155 Total/Cr 0.127 0.506 0.795 0.158Oxygenated 1-hexen-3-ol 23% 1,2-hexanediol 37% 1,2-hexanediol 20%3,4-hexanediol 9% Products 2-hexenal 15% 1-hexen-3-ol 14% 1-hexen-3-one20% C6H10O ketone 9% 1,2-hexanediol 10% 5-hexen-2-ol 14% 2-hexenal 13%2-hexanol 9% formic acid  8% 5-hexen-3-ol 11% butanoic acid 11% C6H12Oalcohol 8% C6H12O  7% ethyl butanoate  5% ethyl ester 1-hexen-3-ol 8%C6H12O  7% 1-pentanol  4% 2-hexen-1-ol  7% 2,3-hexanediol 7%2-hexen-1-ol  4% 2-hexen-1-ol  4% 2-hexanone  4% C6H12O alcohol 7%1-butanol  4% 5-hexen-1-ol  4% 1-hexen-3-ol  3% C6H10O ketone 5% diMebutanoic acid  4% C6H12O  2% C6H12O alcohol  3% 2-hexanone 5% isobutanol 3% C6H12O  1% hexanediol  3% 2-hexenal 4% 2-hexen-1-ol  2% 2-hexenal 1% 2-hexen-1-ol  3% 1,2-hexanediol 2% 3-hexen-2-one  3% Example 61 6263 64 Catalyst G1 K L D Weight (g) 2.1 2.9 2.7 1.9 Reductant 1-Hexene1-Hexene 1-Hexene 2-Hexene Amount 0.5 mL 2 mL 2 mL 0.5 mL Light 40 hrBlue UV 24 h UV 24 h 14 hr Blue Color Green-brown Brown Brown Blue-grayHydrolysis H₂O + CH₃CN 4% H₂O/MeOH 4% H₂O/MeOH H₂O Amount (mL) 15 15 1520 Acid/Cr 0.012 0.003 0.003 0.145 Alcohol/Cr 0.003 0.004 GC-MS/Cr 0.1470.025 0.051 2.318 Total/Cr 0.159 0.031 0.058 2.462 Oxygenated1-hexen-3-ol 18% 5-hexen-2-ol 21% 5-hexen-2-ol 17% 2,3-hexanediol 21%Products C6H12O 10% 5-hexen-2-one 16% 5-hexene-ol 13% 3-hexen-2-one 17%1.2-hexanediol  9% 5-hexen-3-ol 15% 1-hexen-3-ol 10% 4-hexen-3-one 11%C6H12O  8% 1-hexen-3-ol  7% 5-hexen-2-one  9% 3,4-hexanediol  8%2-hexanol  8% isopropanol  7% 1-pentanol  6% 4-hexen-3-ol  8% C6H12O  7%formic acid  7% C11/12 oxygenate  4% 2-Me-1-penten-3-ol  8% C6H14O2  7%1-pentanol  7% formic acid  4% 1-hexen-3-ol  5% 2.3-hexanediol  5%5-hexene-ol  7% isopropanol  4% 2-hexenal  3% C6H12O  4% 4-hexen-3-one 4% 5-hexen-1-ol  3% formic acid  3% acetic acid  3% ethanol  3% C10-12oxygenate  3% C6H12O  2% 2-hexen-1-ol  3% 2-hexenal  3% 1,2-hexandiol 3% 2-butenal  2% formic acid  3% pentanal  3% 4-hexen-1-ol  2% Example65 66 67   Catalyst D D D Weight (g) 2.3 2.2 2.0 Reductant n-Pentanen-Pentane n-Pentane Amount 0.25 mL 1 mL 3 mL Light UV 24 hr UV 24 hr UV24 hr Color Dark blue-gray Green Dark blue-gray Hydrolysis 5% H₂O/MeOH5% H₂O/MeOH 5% H₂O/MeOH Amount (mL) 15 15 15 Acid/Cr 0.13 0.011 0.012Alcohol/Cr GC-MS/Cr 0.323 1.819 1.074 Total/Cr 0.336 1.831 1.086Oxygenated 2-pentanol 46% 2-pentanol 39% 2-pentanol 62% Products1-pentanol 21% 1-pentanol 16% 2-pentanone 18% 2-pentanone 13%2-pentanone 13% 3-pentanone  9% 3-pentanone  6% 3-pentanone  6%1-pentanol  3% 2-hexenal  5% C5H10O  4% 2-pentenal  2% formic acid  3%C10H18O  2% 3-penten-2-one  2% 2-pentenal  2% C7H12O  2% C7H12O  2%2-Me-2-butenal  2% C8H14O  1% formic acid  1%

Examples 68-74

Examples 68-74 were performed to determine the extent of reduction ofthe hexavalent chromium and the average valence after reduction in arepresentative supported chromium catalyst. Table II summarizes theresults. Example 74 was a chromium/silica-titania catalyst containingapproximately 0.8 wt. % chromium and 7 wt. % titania, and having a BETsurface area of 530 m²/g, a pore volume of 2.6 mL/g, and an averageparticle size of 130 um, which was calcined in dry air at 850° C. for 3hr to convert chromium to the hexavalent oxidation state (orange). Thisconverted over 86 wt. % of the chromium into the hexavalent state. ForExamples 68-69, approximate 2 g samples of the catalyst of Example 74were separately charged to a glass reaction vessel and 0.5 mL of liquidisopentane was charged to the vessel. For Examples 70-71, about 1.5 atmof gaseous ethane was charged to the glass bottle. Then, the bottle wasplaced in a light-proof box under blue fluorescent light (approximately2 times the intensity expected from sunlight), and the bottle wascontinuously rotated so that all of the catalyst was exposed to thelight for 24 hr. The final catalyst color is noted in Table II.Afterward, into the bottle, along with the catalyst, was introducedabout 20 mL of a solution of 2 M H₂SO₄. To this was added 5 drops offerroin Fe(+3) indicator. This usually turned a blue-green colorindicating the presence of Fe(III) ions. Next, the solution was titratedto the ferroin endpoint (red color) using a solution of ferrous ammoniumsulfate, which had been previously calibrated by reaction with astandardized 0.1 M sodium dichromate solution. When the solution turnedred, the end point was signaled, and the titrant volume was recorded, tocalculate the oxidation capacity of the catalyst, expressed as wt. %Cr(VI) and as percent reduced, that is, the percent of the originalCr(VI) oxidative power that has been removed by the reduction treatment.The average valence was also computed by multiplying the percent reducedby +3 and subtracting that number from +6.

Of course, this treatment gives only an average oxidation state. Notethat although Table II lists the oxidative power measured as wt. %Cr(VI), in reality all of the chromium could be present in lower valencestates, such as Cr(IV) or Cr(V). Thus, the Cr(VI) value in Table II onlylists the maximum amount of Cr(VI) that could be present. More likely,the reduced chromium catalysts have a combination of several valencestates that produce the measured oxidative power. Note that some of thereduced chromium, and particularly those catalysts reduced with CO, maybe in the divalent state, which would not have been detected in thistest, which stops in the trivalent state.

Example 74 demonstrates that the air-calcined chromium catalystcontained substantially most of its chromium (0.69/0.80=86 wt. %)present as Cr(VI), and it is this Cr(VI) amount that is being reduced inthe light treatment. Therefore, this amount of Cr(VI) serves as thestarting amount, which had an average valence of +6, and which serves asa reference, to which the reduced catalysts are then compared. Examples68-69 were reduced chromium catalysts with an average valence ofapproximately +3.3, with no more than 0.06 wt. % Cr(VI), and with lessthan 10 wt. % of the starting hexavalent chromium still remaining in thehexavalent oxidation state. Examples 70-71 were reduced chromiumcatalysts with an average valence of approximately +4.1, with no morethan 0.26 wt. % Cr(VI), and with less than 40 wt. % of the chromium inthe hexavalent oxidation state. For Examples 72-73, the supportedchromium catalyst was reduced in CO with either blue light or elevatedtemperature, resulting in no oxidative power being measured (0 wt. %Cr(VI) in the table). Thus, the average valence must be no more than +3.But the supported chromium catalyst that was CO-reduced by conventionalmeans (Example 73) is known to have a valence of mostly Cr(II) afterreduction, which is not detected in this test. Accordingly, Examples 72and 73 are listed as less than or equal to +3. Notably, this test cannotdistinguish between Cr(II) and Cr(III) species, but there was nomeasurable amount of hexavalent chromium in Examples 72-73.

TABLE II Examples 68-74 Catalyst Cr (VI) Reduced Average ExampleReductant Treatment Color (g) (wt. %) (wt. %) Valence 68 isopentane Bluelight blue 2.05 0.06 90.8 3.28 24 hr 69 isopentane Blue light blue 2.080.06 90.9 3.27 24 hr 70 ethane Blue light olive 2.14 0.26 62.3 4.13 24hr green 71 ethane Blue light olive 2.30 0.26 61.9 4.14 24 hr green 72CO Blue light blue 2.33 0.00 100 ≤3 24 hr green 73 CO CO reduction blue2.52 0.00 100 ≤3 30 min-350° C. 74 None None orange — 0.69 0 6.00

The invention is described above with reference to numerous aspects andspecific examples. Many variations will suggest themselves to thoseskilled in the art in light of the above detailed description. All suchobvious variations are within the full intended scope of the appendedclaims. Other aspects of the invention can include, but are not limitedto, the following (aspects are described as “comprising” but,alternatively, can “consist essentially of” or “consist of”):

Aspect 1. A process for converting an olefin reactant into a diolcompound, the process comprising:

(i) contacting the olefin reactant and a supported chromium catalystcomprising chromium in a hexavalent oxidation state to reduce at least aportion of the supported chromium catalyst to form a reduced chromiumcatalyst (e.g., with at least a portion of the chromium on the reducedchromium catalyst having at least one bonding site with a hydrocarboxygroup (a —O-hydrocarbon group)); and

(ii) hydrolyzing the reduced chromium catalyst to form a reactionproduct comprising the diol compound.

Aspect 2. A process for converting an olefin reactant into a diolcompound, the process comprising:

(i) irradiating the olefin reactant and a supported chromium catalystcomprising chromium in a hexavalent oxidation state with a light beam ata wavelength in the UV-visible spectrum to reduce at least a portion ofthe supported chromium catalyst to form a reduced chromium catalyst; and

(ii) hydrolyzing the reduced chromium catalyst to form a reactionproduct comprising the diol compound.

Aspect 3. The process defined in aspect 1 or 2, wherein the olefinreactant comprises a linear olefin compound (e.g., a normal α-olefin), abranched olefin compound, a cyclic olefin compound, or a combinationthereof.

Aspect 4. The process defined in aspect 1 or 2, wherein the olefinreactant comprises any suitable carbon number olefin compound or anycarbon number olefin compound disclosed herein, e.g., a C₂ to C₃₆ olefincompound, a C₂ to C₁₈ olefin compound, a C₂ to C₁₂ olefin compound, or aC₂ to C₈ olefin compound (e.g., a C₂-C₁₈ normal α-olefin or a C₂-C₈normal α-olefin).

Aspect 5. The process defined in aspect 1 or 2, wherein the olefinreactant comprises ethylene, propylene, butene, pentene, hexene,heptene, octene, decene, dodecene, tetradecene, hexadecene, octadecene,or any combination thereof.

Aspect 6. The process defined in aspect 1 or 2, wherein the olefinreactant comprises ethylene, propylene, 1-butene, 2-butene,3-methyl-1-butene, isobutylene, 1-pentene, 2-pentene,3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene,3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene, 1-nonene,1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-pentadecene, 1-hexadecene, 1-octadecene, styrene, or any combinationthereof.

Aspect 7. The process defined in aspect 1 or 2, wherein the olefinreactant comprises ethylene, propylene, 1-butene, 1-pentene, 1-hexene,1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, or any combination thereof.

Aspect 8. The process defined in aspect 1 or 2, wherein the olefinreactant comprises ethylene, propylene, 1-butene, 1-pentene, 1-hexene,or any combination thereof.

Aspect 9. The process defined in aspect 1 or 2, wherein the olefinreactant comprises norbornene, cyclopentene, cyclohexene, cycloheptene,cyclooctene, or any combination thereof.

Aspect 10. The process defined in aspect 1 or 2, wherein the olefinreactant comprises ethylene (or propylene), and the diol compoundcomprises ethanediol (or propanediol).

Aspect 11. The process defined in aspect 1 or 2, wherein the olefinreactant comprises 1-pentene, and the diol compound comprises apentanediol.

Aspect 12. The process defined in aspect 1 or 2, wherein the olefinreactant comprises 1-hexene, and the diol compound comprises ahexanediol.

Aspect 13. The process defined in any one of the preceding aspects,wherein the diol compound comprises a 1,2-diol compound.

Aspect 14. The process defined in any one of the preceding aspects,wherein the diol compound comprises a 1,3-diol compound.

Aspect 15. The process defined in any one of the preceding aspects,wherein the diol compound comprises a 2,3-diol compound.

Aspect 16. The process defined in any one of the preceding aspects,wherein the olefin reactant comprises a Cn olefin compound, and the diolcompound comprises a Cn diol compound.

Aspect 17. The process defined in aspect 16, wherein n is any suitableinteger or an integer in any range disclosed herein, e.g., from 2 to 36,from 2 to 18, from 2 to 12, or from 2 to 8.

Aspect 18. The process defined in any one of the preceding aspects,wherein the reaction product further comprises a carbonyl compound,e.g., an aldehyde, a ketone, a carboxylic acid, or any combinationthereof.

Aspect 19. The process defined in any one of the preceding aspects,wherein the reaction product further comprises an alcohol compound (amono-alcohol compound).

Aspect 20. The process defined in any one of the preceding aspects,wherein the supported chromium catalyst and the reduced chromiumcatalyst comprise any suitable amount of chromium or an amount in anyrange disclosed herein, e.g., from about 0.01 to about 50 wt. %, fromabout 0.01 to about 10 wt. %, from about 0.05 to about 15 wt. %, fromabout 0.1 to about 15 wt. %, from about 0.2 to about 10 wt. %, fromabout 0.1 to about 5 wt. %, from about 0.5 to about 30 wt. %, or fromabout 0.5 to about 2.5 wt. % of chromium, based on the weight of thesupported chromium catalyst or the reduced chromium catalyst.

Aspect 21. The process defined in any one of the preceding aspects,wherein the reduced chromium catalyst comprises any suitable amount ofchromium in an average oxidation state of +5 or less, or an amount inany range disclosed herein, e.g., from about 0.01 to about 50 wt. %,from about 0.01 to about 10 wt. %, from about 0.05 to about 15 wt. %,from about 0.1 to about 15 wt. %, from about 0.2 to about 10 wt. %, fromabout 0.1 to about 5 wt. %, from about 0.5 to about 30 wt. %, or fromabout 0.5 to about 2.5 wt. % of chromium in an average oxidation stateof +5 or less, based on the weight of the reduced chromium catalyst.

Aspect 22. The process defined in any one of the preceding aspects,wherein the amount of the chromium of the supported chromium catalyst ina hexavalent oxidation state is at least about 10 wt. %, at least about20 wt. %, at least about 40 wt. %, at least about 60 wt. %, at leastabout 80 wt. %, or at least about 90 wt. %, based on the total amount ofchromium on the supported chromium catalyst, and/or the amount ofchromium of the reduced chromium catalyst in a hexavalent oxidationstate is (from 0 wt. %, from about 0.5 wt. %, from about 1 wt. %, orfrom about 2 wt. % to) less than or equal to about 50 wt. %, less thanor equal to about 40 wt. %, less than or equal to about 30 wt. %, orless than or equal to about 15 wt. %, based on the total amount ofchromium on the reduced chromium catalyst.

Aspect 23. The process defined in any one of the preceding aspects,wherein at least about 10 wt. %, at least about 20 wt. %, at least about40 wt. %, at least about 60 wt. %, at least about 80 wt. %, or at leastabout 90 wt. %, of the supported chromium catalyst is reduced to formthe reduced chromium catalyst, based on the total amount of thesupported chromium catalyst.

Aspect 24. The process defined in any one of the preceding aspects,wherein the chromium in the reduced chromium catalyst has an averagevalence of less than or equal to about 5.25, less than or equal to about5, less than or equal to about 4.75, less than or equal to about 4.5,less than or equal to about 4.25, or less than or equal to about 4.

Aspect 25. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst compriseany suitable solid oxide or any solid oxide disclosed herein, e.g.,silica, alumina, silica-alumina, silica-coated alumina, aluminumphosphate, aluminophosphate, heteropolytungstate, titania, zirconia,magnesia, boria, zinc oxide, silica-titania, silica-zirconia,alumina-titania, alumina-zirconia, zinc-aluminate, alumina-boria,alumina borate, silica-boria, aluminophosphate-silica, titania-zirconia,or any combination thereof.

Aspect 26. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisesilica, silica-alumina, silica-coated alumina, silica-titania,silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria,aluminophosphate-silica, alumina, alumina borate, or any combinationthereof.

Aspect 27. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprise achemically-treated solid oxide comprising a solid oxide (e.g., as inaspect 25 or 26, such as silica, alumina, silica-alumina,silica-titania, silica-zirconia, silica-yttria, aluminophosphate,zirconia, titania, thoria, or stania) treated with anelectron-withdrawing anion.

Aspect 28. The process defined in aspect 27, wherein theelectron-withdrawing anion comprises sulfate, bisulfate, fluoride,chloride, bromide, iodide, fluorosulfate, fluoroborate, phosphate,fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, phospho-tungstate, tungstate, molybdate, or anycombination thereof.

Aspect 29. The process defined in aspect 27 or 28, wherein thechemically-treated solid oxide contains from about 1 to about 30 wt. %,from about 2 to about 20 wt. %, from about 2 to about 15 wt. %, fromabout 3 to about 12 wt. %, or from 4 to 10 wt. %, of theelectron-withdrawing anion, based on the total weight of thechemically-treated solid oxide.

Aspect 30. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprise achemically-treated solid oxide comprising fluorided alumina, chloridedalumina, bromided alumina, sulfated alumina, fluorided silica-alumina,chlorided silica-alumina, bromided silica-alumina, sulfatedsilica-alumina, fluorided silica-zirconia, chlorided silica-zirconia,bromided silica-zirconia, sulfated silica-zirconia, fluoridedsilica-titania, fluorided silica-coated alumina, fluorided-chloridedsilica-coated alumina, sulfated silica-coated alumina, phosphatedsilica-coated alumina, or any combination thereof.

Aspect 31. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisechromium/silica, chromium/silica-titania,chromium/silica-titania-magnesia, chromium/silica-alumina,chromium/silica-coated alumina, chromium/aluminophosphate,chromium/alumina, chromium/alumina borate, or any combination thereof.

Aspect 32. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisechromium/silica-titania, and the supported chromium catalyst and thereduced chromium catalysts comprise any suitable amount of titanium oran amount in any range disclosed herein, e.g., from about 0.1 to about20 wt. %, from about 0.5 to about 15 wt. %, from about 1 to about 10 wt.%, or from about 1 to about 6 wt. %, based on the weight of thesupported chromium catalyst or the reduced chromium catalyst.

Aspect 33. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisechromium/sulfated alumina, chromium/fluorided alumina,chromium/fluorided silica-alumina, chromium/fluorided silica-coatedalumina, or any combination thereof.

Aspect 34. The process defined in any one of aspects 1-24, wherein thesupported chromium catalyst and the reduced chromium catalyst comprise azeolite.

Aspect 35. The process defined in aspect 34, wherein the supportedchromium catalyst and the reduced chromium catalyst comprise a mediumpore zeolite, a large pore zeolite, or a combination thereof.

Aspect 36. The process defined in aspect 34, wherein the zeolitecomprises a ZSM-5 zeolite, a ZSM-11 zeolite, an EU-1 zeolite, a ZSM-23zeolite, a ZSM-57 zeolite, an ALPO4-11 zeolite, an ALPO4-41 zeolite, aFerrierite framework type zeolite, or a combination thereof.

Aspect 37. The process defined in aspect 34, wherein the supportedchromium catalyst and the reduced chromium catalyst comprise anL-zeolite, a Y-zeolite, a mordenite, an omega zeolite, and/or a betazeolite.

Aspect 38. The process defined in any one of aspects 34-37, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisethe zeolite and any suitable amount of binder or an amount in any rangedisclosed herein, e.g., from about 3 wt. % to about 35 wt. %, or fromabout 5 wt. % to about 30 wt. % binder, based on the weight of thesupported chromium catalyst and/or the reduced chromium catalyst.

Aspect 39. The process defined in any one of the preceding aspects,wherein the supported chromium catalyst and the reduced chromiumcatalyst have any suitable pore volume (total) or a pore volume (total)in any range disclosed herein, e.g., from about 0.1 to about 5 mL/g,from about 0.15 to about 5 mL/g, from about 0.1 to about 3 mL/g, or fromabout 0.15 to about 2 mL/g.

Aspect 40. The process defined in any one of the preceding aspects,wherein the supported chromium catalyst and the reduced chromiumcatalyst have any suitable BET surface area or a BET surface area in anyrange disclosed herein, e.g., from about 50 to about 2000 m²/g, fromabout 50 to about 700 m²/g, from about 50 to about 400 m²/g, from about100 to about 1200 m²/g, from about 150 to about 525 m²/g, or from about300 to about 1000 m²/g.

Aspect 41. The process defined in any one of the preceding aspects,wherein the supported chromium catalyst and the reduced chromiumcatalyst are in any suitable shape or form or any shape or formdisclosed herein, e.g., powder, round or spherical (e.g., spheres),ellipsoidal, pellet, bead, cylinder, granule (e.g., regular and/orirregular), trilobe, quadralobe, ring, wagonwheel, monolith, or anycombination thereof.

Aspect 42. The process defined in any one aspects 1-41, wherein thesupported chromium catalyst and the reduced chromium catalyst have anysuitable average (d0) particle size or an average (d0) particle size inany range disclosed herein, e.g., from about 10 to about 500 microns,from about 25 to about 250 microns, or from about 20 to about 100microns.

Aspect 43. The process defined in any one aspects 1-41, wherein thesupported chromium catalyst and the reduced chromium catalyst comprisepellets or beads having any suitable average size or an average size inany range disclosed herein, e.g., from about 1/16 inch to about ½ inch,or from about ⅛ inch to about ¼ inch.

Aspect 44. The process defined in any one of aspects 2-43, wherein thewavelength comprises a single wavelength or a range of wavelengths inthe visible spectrum (from 380 nm to 780 nm).

Aspect 45. The process defined in any one of aspects 2-43, wherein thewavelength comprises a single wavelength or a range of wavelengths inthe 200 nm to 750 nm range.

Aspect 46. The process defined in any one of aspects 2-43, wherein thewavelength comprises a single wavelength or a range of wavelengths inthe 300 to 750 nm range, the 350 nm to 650 nm range, the 300 nm to 500nm range, or the 300 nm to 400 nm range.

Aspect 47. The process defined in any one of aspects 2-43, wherein thewavelength comprises a single wavelength or a range of wavelengths below600 nm, below 525 nm, or below 500 nm.

Aspect 48. The process defined in any one of aspects 2-47, wherein thewavelength is a single wavelength.

Aspect 49. The process defined in any one of aspects 2-47, wherein thewavelength is a range of wavelengths spanning at least 25 nm, at least50 nm, at least 100 nm, or at least 200 nm.

Aspect 50. The process defined in any one of aspects 2-49, wherein thelight beam has any suitable intensity or an intensity in any rangedisclosed herein, e.g., at least about 500 lumens, at least about 1000lumens, at least about 2000 lumens, at least about 5000 lumens, at leastabout 10,000 lumens, or at least about 20,000 lumens.

Aspect 51. The process defined in any one of aspects 2-50, wherein thelight beam has any suitable power or any power disclosed herein, e.g.,at least about 50 watts, at least about 100 watts, at least about 200watts, at least about 500 watts, at least about 1,000 watts, or at leastabout 2,000 watts.

Aspect 52. The process defined in any one of aspects 2-51, wherein thesupported chromium catalyst is irradiated with any suitable illuminanceor any illuminance disclosed herein, e.g., at least about 100 lux, atleast about 500 lux, at least about 1000 lux, at least about 2000 lux,at least about 5000 lux, at least about 10,000 lux, at least about20,000 lux, or at least about 100,000 lux.

Aspect 53. The process defined in any one of the preceding aspects,wherein the contacting step (or the irradiating step) is conducted atany suitable temperature or any temperature disclosed herein, e.g., lessthan about 200° C., less than about 100° C., less than about 40° C.,from about −100° C. to about 100° C., from about 0° C. to about 100° C.,or from about 10° C. to about 40° C.

Aspect 54. The process defined in any one of the preceding aspects,wherein the contacting step (or the irradiating step) is conducted forany suitable contacting (or exposure) time or for any contacting (orexposure) time disclosed herein, e.g., from about 15 sec to about 48 hr,from about 1 min to about 6 hr, from about 1 min to about 15 min, orfrom about 1 hr to about 8 hr.

Aspect 55. The process defined in any one of the preceding aspects,wherein the molar ratio of the olefin reactant to chromium (of thesupported chromium catalyst) is in any suitable range or any rangedisclosed herein, e.g., at least about 0.25:1, at least about 0.5:1, atleast about 1:1, at least about 10:1, at least about 100:1, at leastabout 1000:1, or at least about 10,000:1.

Aspect 56. The process defined in any one of aspects 1-55, wherein theolefin reactant is in a gas phase during the contacting step (or theirradiating step).

Aspect 57. The process defined in any one of aspects 1-55, wherein theolefin reactant is in a liquid phase during the contacting step (or theirradiating step).

Aspect 58. The process defined in any one of aspects 1-55, wherein theprocess comprises contacting (or irradiating) a slurry of the supportedchromium catalyst in the olefin reactant.

Aspect 59. The process defined in any one of aspects 1-55, wherein theprocess comprises contacting the olefin reactant with a fluidized bed ofthe supported chromium catalyst (or irradiating while contacting orfluidizing the supported chromium catalyst).

Aspect 60. The process defined in any one of aspects 1-55, wherein theprocess comprises contacting the olefin reactant (e.g., in a gas phaseor in a liquid phase) with a fixed bed of the supported chromiumcatalyst (or irradiating while contacting).

Aspect 61. The process defined in any one of the preceding aspects,wherein the step of contacting (or irradiating) the olefin reactant withthe supported chromium catalyst is conducted at any suitable WHSV or aWHSV in any range disclosed herein, e.g., from about 0.01 hr⁻¹ to about500 hr⁻¹, or from about 0.1 hr⁻¹ to about 10 hr⁻¹.

Aspect 62. The process defined in any one of the preceding aspects,wherein the hydrolyzing step is conducted at any suitable temperature orany temperature disclosed herein, e.g., less than about 200° C., lessthan about 100° C., less than about 40° C., from about 0° C. to about100° C., or from about 10° C. to about 40° C.

Aspect 63. The process defined in any one of the preceding aspects,wherein the hydrolyzing step comprises contacting the reduced chromiumcatalyst with a hydrolysis agent.

Aspect 64. The process defined in aspect 63, wherein the hydrolysisagent comprises any suitable hydrolysis agent or any hydrolysis agentdisclosed herein, e.g., water, steam, an alcohol agent, an acid agent,an alkaline agent, or any combination thereof.

Aspect 65. The process defined in aspect 63 or 64, wherein thehydrolysis agent further comprises any suitable reducing agent or anyreducing agent disclosed herein, e.g., ascorbic acid, an iron (II)reducing agent, a zinc reducing agent, or any combination thereof.

Aspect 66. The process defined in any one of the preceding aspects,wherein a conversion of the olefin reactant (or a yield to the diolcompound) is any percent conversion (or yield) disclosed herein, e.g.,at least about 2 wt. %, at least about 5 wt. %, at least about 10 wt. %,or at least about 15 wt. % (and up to about 99 wt. %, about 95 wt. about90 wt. %, about 80 wt. %, about 70 wt. %, or about 50 wt. %).

Aspect 67. The process defined in any one of the preceding aspects,wherein a single pass conversion of the olefin reactant (or a singlepass yield to the diol compound) is any single pass percent conversion(or single pass yield) disclosed herein, e.g., at least about 2 wt. %,at least about 5 wt. %, at least about 10 wt. %, or at least about 15wt. % (and up to about 99 wt. %, about 95 wt. %, about 90 wt. %, about80 wt. %, about 70 wt. %, or about 50 wt. %).

Aspect 68. The process defined in any one of the preceding aspects,wherein the yield to the diol compound per mole of chromium (VI) in thesupported chromium catalyst is any molar ratio based on moles ofchromium (VI) disclosed herein, e.g., at least about 0.01, at leastabout 0.05, at least about 0.1, or at least about 0.25 moles (and up to2, up to about 1.8, up to about 1.6, up to about 1.4, up to about 1.2,or up to about 1 mole) of the diol compound.

Aspect 69. The process defined in any one of the preceding aspects,further comprising a step of separating at least a portion (and in somecases, all) of the olefin reactant from the reaction product after step(ii) to produce a separated portion of the olefin reactant using anysuitable technique or any technique disclosed herein, e.g., extraction,filtration, evaporation, distillation, or any combination thereof.

Aspect 70. The process defined in aspect 69, wherein the separatedportion of the olefin reactant is recycled and contacted (or irradiated)with the supported chromium catalyst again.

Aspect 71. The process defined in any one of the preceding aspects,further comprising a step of separating at least a portion (and in somecases, all) of the diol compound from the reaction product using anysuitable technique or any technique disclosed herein, e.g., extraction,filtration, evaporation, distillation, or any combination thereof.

Aspect 72. The process defined in any one of the preceding aspects,further comprising a step of separating at least a portion (and in somecases, all) of the reduced chromium catalyst from the reaction productafter step (ii) to produce a separated portion of the reduced chromiumcatalyst using any suitable technique or any technique disclosed herein,e.g., extraction, filtration, evaporation, distillation, or anycombination thereof.

Aspect 73. The process defined in any one of the preceding aspects,further comprising a step of (iii) calcining the reduced chromiumcatalyst or the separated portion of the reduced chromium catalyst toregenerate the supported chromium catalyst.

Aspect 74. The process defined in aspect 73, wherein calcining comprisessubjecting the reduced chromium catalyst or the separated portion of thereduced chromium catalyst to an oxidizing atmosphere at any suitablepeak temperature and time conditions or any peak temperature and timeconditions disclosed herein, e.g., a peak temperature from about 300° C.to about 1000° C., from about 500° C. to about 900° C., or from about550° C. to about 870° C., for a time period of from about 1 min to about24 hr, from about 1 hr to about 12 hr, or from about 30 min to about 8hr.

We claim:
 1. A process for converting an olefin reactant into a diolcompound, the process comprising: (i) irradiating the olefin reactantand a supported chromium catalyst comprising chromium in a hexavalentoxidation state with a light beam at a wavelength in the UV-visiblespectrum to reduce at least a portion of the supported chromium catalystto form a reduced chromium catalyst; (ii) hydrolyzing the reducedchromium catalyst to form a reaction product comprising the diolcompound; and (iii) separating at least a portion of the olefin reactantfrom the reaction product, wherein the at least a portion of the olefinreactant is recycled and irradiated with the supported chromium catalystagain.
 2. The process of claim 1, wherein the olefin reactant comprisesa C₂ to C₃₆ linear, branched, or cyclic olefin compound.
 3. The processof claim 1, wherein the olefin reactant comprises ethylene, propylene,butene, pentene, hexene, heptene, octene, decene, dodecene, tetradecene,hexadecene, octadecene, or any combination thereof.
 4. The process ofclaim 1, wherein the supported chromium catalyst contains from about0.01 to about 50 wt. % of chromium, based on the weight of the supportedchromium catalyst.
 5. The process of claim 1, wherein the reducedchromium catalyst contains chromium having an average valence of lessthan or equal to about 5.25.
 6. The process of claim 1, wherein thewavelength comprises a single wavelength or a range of wavelengths in arange from about 200 nm to about 750 nm.
 7. The process of claim 1,wherein the irradiating step is conducted at a temperature from about−100° C. to about 100° C.
 8. The process of claim 1, wherein the processcomprises: contacting the olefin reactant with a fluidized bed of thesupported chromium catalyst, and irradiating while contacting; orcontacting the olefin reactant with a fixed bed of the supportedchromium catalyst, and irradiating while contacting.
 9. The process ofclaim 1, wherein: hydrolyzing is conducted at a temperature from about0° C. to about 100° C.; and hydrolyzing comprises contacting the reducedchromium catalyst with a hydrolysis agent comprising water, steam, analcohol agent, an acid agent, an alkaline agent, or any combinationthereof.
 10. The process of claim 1, wherein a conversion of the olefinreactant is at least about 10 wt. %.
 11. The process of claim 1, furthercomprising: separating at least a portion of the reduced chromiumcatalyst from the reaction product after step (ii); and calcining the atleast a portion of the reduced chromium catalyst to regenerate thesupported chromium catalyst.
 12. The process of claim 1, wherein: theolefin reactant comprises ethylene and the diol compound comprisesethanediol; the olefin reactant comprises propylene and the diolcompound comprises propanediol; the olefin reactant comprises 1-penteneand the diol compound comprises a pentanediol; or the olefin reactantcomprises 1-hexene and the diol compound comprises a hexanediol.
 13. Aprocess for converting an olefin reactant into a diol compound, theprocess comprising: (i) irradiating the olefin reactant and a supportedchromium catalyst comprising chromium in a hexavalent oxidation statewith a light beam at a wavelength in the UV-visible spectrum to reduceat least a portion of the supported chromium catalyst to form a reducedchromium catalyst; and (ii) hydrolyzing the reduced chromium catalyst toform a reaction product comprising the diol compound; wherein a molaryield of the diol compound is from about 0.01 to about 2 moles of thediol compound per mole of chromium (VI) in the supported chromiumcatalyst.
 14. The process of claim 13, wherein the diol compoundcomprises a 1,2-diol compound.
 15. The process of claim 13, wherein: thesupported chromium catalyst contains from about 0.2 to about 10 wt. % ofchromium, based on the weight of the supported chromium catalyst; andthe olefin reactant comprises ethylene, propylene, butene, pentene,hexene, heptene, octene, decene, dodecene, tetradecene, hexadecene,octadecene, or any combination thereof.
 16. The process of claim 15,wherein the molar yield of the diol compound is from about 0.05 to about1.8 moles of the diol compound per mole of chromium (VI) in thesupported chromium catalyst.